OklahomaSkies.Net

INCREDIBLE Time lapse Of Oklahoma Supercell!

2011-06-03T22:42:00.001-05:00

Just thought I'd share an AMAZING time lapse of one of the most textbook supercells I have ever seen occurring just southeast of the Oklahoma City metro area during the evening hours of May 21, 2011. This same supercell spawned a very photogenic "cone shaped" tornado near Ada, OK. Unfortunately during this time I was graduating high school and was not able to make it out to this storm. These past two years have been very frustrating for me in terms of missing/not making it to storms and I am already preparing myself for next year's storm season as this year is pretty much done in the plains. While there certainly was not a lack of tornadoes this year, they have occurred almost anywhere but the chase-able terrain of the plains. Instead much of the southern and central plains has been dealing with a "modern dust bowl" with severe drought conditions. In fact Amarillo, TX has experienced its driest start to the year on record with only 0.01" of rain falling so far this year and that came with yesterday's line of high based showers/storms!!

Meanwhile we are closely monitoring Invest 94L in the central Caribbean right now. It is currently rather broad and disorganized but the environmental conditions are as the NHC depicts "generally favorable for development" and they have dubbed the system a 30% chance of becoming a tropical cyclone. For those who don't know hurricanes are my second interest and you'll likely be hearing a lot from me about this year's hurricane season in the coming weeks/months.

Binger, Guthrie Tornado Oklahoma's First EF-5 Since 1999

2011-06-01T19:45:00.004-05:00

Earlier today the National Weather Service(NWS) in Norman upgraded the Binger, El Reno, Piedmont, Guthrie tornado to an EF-5 with wind speeds greater than 210mph. See the statement below.

STORM 2... BINGER-EL RENO-PIEDMONT-GUTHRIE

PRELIMINARY DATA...
EVENT DATE: MAY 24, 2011
EVENT TYPE: TORNADO
EF RATING: EF-5
ESTIMATED PEAK WINDS (MPH): GREATER THAN 210 MPH
INJURIES/FATALITIES: UNKNOWN/9
EVENT START LOCATION AND TIME: 8 WNW BINGER 3:30 PM CDT
EVENT END LOCATION AND TIME: 4 NE GUTHRIE 5:35 PM CDT
DAMAGE PATH LENGTH (IN MILES): 75 MILES
DAMAGE WIDTH: UNKNOWN
NOTE: RATING BASED ON UNIVERSITY OF OKLAHOMA MOBILE DOPPLER RADAR
MEASUREMENTS.

[Read the complete public information statement here...]

This tornado was responsible for 9 of the 10 deaths that occurred in Oklahoma last week. A wind speed of 210mph was recorded by the University of Oklahoma mobile doppler radar and this tornado was likely the strongest since May 3rd 1999 when a 318mph wind gust was measured by DOW(Doppler On Wheels). This is also Oklahoma's first EF-5 since May 3rd 1999 as well.

Map showing the 59 F5/EF tornadoes that have occurred
in the U.S. from 1950-2010. This is not including the 5
tornadoes that have occurred in 2011...

The Binger, Guthrie tornado is the latest EF-5 to wreak havoc in this year's deadly tornado season making for a total of 5 tornadoes this year that have been given the highest rating on the enhanced fujita scale.

Is this an unprecedented record? No. While 2011 has seen the most EF-5 tornadoes since 1974 when there was 6 F-5 tornadoes documented it is not the only time there has been this many tornadoes of this strength recorded.[ see list of F-5/EF-5 tornadoes since 1950...]

What is unprecedented, is the amount of deaths that have occurred this year. The SPC has counted over 518 deaths due to tornadoes this year making it the deadliest tornado year since 1953(the last time tornado deaths approached and exceeded 500). Another interesting fact is that this year's tornado deaths alone are equivalent to the total of tornado deaths in the last 5 decades!

Why have so many people died this year? The answer is not simple, in fact we are still unsure as to why there has been so many deaths this year. I believe that the answer lies in the fact that we have had several large and violent tornadoes impact highly populated areas along with the fact that people are NOT as prepared as we think they should be. In a survey that accumulated votes after asking people how much time they needed to prepare for an impending tornado 91% averaged 10 minutes and under. The average warning lead time during the April 27, 2011 tornado outbreak was 31 minutes and in Joplin, MO it was 27 minutes. If it takes people less than 10 minutes to seek shelter than this is obviously MORE than enough time for people to have moved to their safe spot. This tells me that people are simply ignoring warnings or have the attitude that "it won't happen to me." and this to me is alarming. While it is unfortunate that so many people have lost their possessions and/or lives, this year has definitely uncovered the truth about people's preparedness(or lack thereof) and how IMPORTANT it is to BE prepared. It is true that the chances of anyone's house being hit by a tornado is very slim but you need to be prepared for the time disaster is imminent. Like earthquakes, tornadoes are low probability events but have very high impacts and the importance of being prepared for such events cannot be stressed enough. What do you guys think? Do you think that people are overexposed to tornado warnings/sirens and therefore do not take them seriously anymore? Are people really this unprepared? Are the amount of deaths this year related to the high impact of the tornadoes themselves in junction to highly populated areas? So many questions but a limited amount of answers. One thing I can say is that "Global Warming" is NOT the cause of this year's record breaking tornado year.

Rare tornado kills 4 in Massachusetts.

RAW video of a massive transparent tornado crossing the Connecticut River near Springfield, MA this evening. The tornado caused EF-2 to EF-3 damage to parts of town and sadly killed 4 people and injuring many more. A tornado of this magnitude occurring in Massachusetts is rare but has happened before in the past. The tornado has tied 2011 with 1973 as the deadliest tornado year for Massachusetts since the powerful EF-4 Worcester, MA tornado that killed 90 people. There were actually two tornadoes this evening that hit Springfield between 4:30 and 6:20PM EDT responsible for the deaths/damage with the one in the video above likely doing the most damage.

6/3/11 12:12PM CDT EDIT: Replaced broken link for the public information statement above. Should be working now.

Tropical Troubles Coming along with Dangerous Heat!!

2011-05-29T16:30:00.001-05:00

Can someone please turn the darn air conditioner on PLEASE!!?? Current temperatures across the region are in the upper 80s to even as high as 105 in Beaver, Oklahoma. Dewpoints in the mid to upper 60s are combing with this heat to create heat index values in the low to mid 90s to even as high as 104 in Buffalo and 103 in Hollis. Windy conditions are also across the area as sustained winds of 15-30 mph with gusts over 40 mph. However there maybe some relief coming but it will be brief at best. A quick moving upper low will move across the area Monday night into Tuesday and there maybe just enough lift to cause a couple strong thunderstorms to develop. There will be enough instability and just enough shear to sustain thunderstorms which maybe super cellular in nature with large hail and damaging winds the main threats. A slight risk of severe weather has been issued for this reason. However a threat for widespread damaging winds and a tornado or two will exist in the moderate risk area as a derecho is probable and wind fields while very strong are unidirectional and looking at skew-t soundings Souix City would be the best chance of seeing a tornado as there is decent low level directional shear however OSN doesn't plan to chase tomorrow.

After this small chance of thunderstorms Tuesday the same ole same ole will be the rule with a typical summertime pattern residing across the area as a ridge stays put. Towards the later half of the area temperatures are just going to get flat out brutal as max temperatures in the mid to upper 90s will be comen and combined with dew points in the upper 60s to low 70s heat index values will reach the century mark if not go over and heat advisories very well maybe required. However while the weather maybe quiet across this neck of woods things cannot be said in the tropics- that's right the tropics. June 1st is the official start of hurricane season. NOAA is predicting anywhere from 12-18 named storms, 6-10 hurricanes and 3-6 major hurricanes. However my prediction- while similar I am going with 15-20 named storms, 8-10 hurricanes and 4-7 major hurricanes. Once thing can be said about this season- it will be active. I have noticed over the past couple days models- particularly the NGP, CMC and to a lesser degree the GFS (which the 0z run last night showed a decent tropical storm between the Louisiana and Mississippi borders). While something is stirring the pot that shear is tad to high right now but is forecasted to weaken over the next 10-15 days. One thing thats already concerning me is the MJO (aka Madden Julian Oscillation). Below is the forecasted upward motion during the next few weeks.

Notice that darker green area on days 10-15 thats when we are watching for potential development.

Well well wonders never seize there's the CMC model at hour 126 aka 7-8 days down the line. If this was to pan out this system would be named "Arlene". This is still a ways out and allot can change likely will. But on the upward motion chart also notice that brown thats dry air and not really favorable for tropical development. In closing- prepare for the heat- avoid doing stressful things during the peak heating hours- do what you gotta take care of early in the morning, drink plenty of water, avoid alcoholic drinks like beer as is dehydrates you.

Remarkable Week Of Killer Tornadoes...

2011-05-27T13:13:00.001-05:00

2011 will surely go down as one of the most active/deadliest tornado years in history and we still have climatologically speaking another month to go before we see a dramatic decrease in the number of expected tornado reports. Whether or not mother nature will follow this trend remains to be seen as this year has been anything but normal.

Joplin, MO Tornado among the top 10 deadliest tornadoes in U.S. history.
132 are dead in Joplin, MO after an EF-5 tornado with estimated winds exceeding 200mph obliterated 75% of the city shortly after 5:40pm CDT 5/22/11. 156 people are unaccounted for and the death toll is likely to creep higher in the coming days and weeks. SPC has deemed this tornado as the 8th deadliest U.S. tornado of all time and the deadliest since 1947 when a violent F-5 tornado killed 181 in Woodward, OK.

From left to right shows the base reflectivity and base velocity as the tornado was tearing through the southeastern sides of town. Notice the now infamous debris ball represented by the blob of higher dbzs indicating debris being lofted high into the atmosphere. These signatures are almost always associated with violent/damaging tornadoes and was also the case with Tuscaloosa, AL during the April 27, 2011 tornado outbreak.

Two days later mother nature unleashed her fury again, this time in the southern plains with several large and long tracked tornadoes doing considerable damage to the southern and northwestern suburbs of Oklahoma City.

Tornado near Goldsby, OK during Tuesday's tornado outbreak in Oklahoma. Photo credit goes to Tim Eckstein.

A rare high risk for severe weather was issued Tuesday including a 45% hatched risk for large/violent tornadoes. The last time a 45% hatched risk for tornadoes was issued was back on April 27, 2011 during the busiest and most active tornado day in world history across the southeast. NWS Rick Smith says that a 45% hatched risk for tornadoes is a rarity and usually issued once every 5-10 years! Sure enough early in the afternoon supercells exploded along the dryline and approached the I-35 corridor with violent tornadoes during the evening rush hour. Several communities were hard hit, including Piedmont, El Reno, Binger, Chickasha, Newcastle, Blanchard, Moore, Washington, and Goldsby. These tornadoes were given preliminary ratings of EF-4 and higher ratings are possible according to the NWS as additional surveying is done.

Sadly 10 people also died in the tornadoes including the 3 year old boy who was found near Falcon lake after a mass search was underway prior to. A total of 16 people were killed all together in KS/OK/TX.

Mesonet station records rare data from El Reno Tornado.
The El Reno mesonet station recorded a wind gust of 151mph along the outer edge of the tornado during Tuesday's tornado outbreak. Data indicated a pressure drop to 940mb as the tornado approached. Such data is extremely rare given that usually these instruments fail in the event of high winds.

Here is our chase video from Tuesday. We were off to a late start due to work but managed to videotape a beautiful tornado near Goldsby, OK as it was roping out. Previously the tornado was much larger and did EF-4 damage. We continued to chase the supercells across south central Oklahoma the remainder of the evening witnessing several spectacular wall clouds. The close proximity of the storms later that evening created a lot of interference which prevented additional tornadoes farther east.

Tornado Outbreak Once Again!!

2011-05-25T09:58:00.000-05:00

After another tornado outbreak yesterday we are bracing for another tornado outbreak today. The storm prediction center has issued another high risk for severe weather for northeast Arkansas, southeast Missouri, western Tennessee and Kentucky and southern Illinois. This is where a 30 percent chance for tornadoes have been introduced but based out of the 12z sounding out of Little Rock, Arkansas it wouldn't surprise me to see a high risk introduced into central and eastern Arkansas by the next outlook. The sounding shows an already unstable air mass with 1900 j/kg cape, 500 helicity (potential for rotating winds) and energy helicity values at 7.

Right now a vorticity maxima is located over southern Kansas with a warm front extending from northern Missouri into Illinois and Indiana. Its south of the warm front where theres some breaks in the clouds and allowing things to go really wild. Meanwhile a cold front located east of Oklahoma City along with a dry line extending from the cold front. It's a rarity to get a dry line this far east but when it does look out cause things are going to go very wild. Later on as the day progresses, a warm, moist and extremely unstable airmass will reside across the region with cape values over 4000 j/kg likely. The combination of an extremely unstable airmass, helicity values over 250 M2^s2, 50-60 knots of shear with a 70 knot mid level speed max, and a low level jet cranking of 40 knots will create quite an ideal environment for tornadic supercells to develop. Once again this will be kind of environment also that can go from wallcloud to wedge tornado in minutes and some of them will be strong tornadoes- especially in the moderate and high risk area. Steep lapse rates and low freezing levels combined with extreme instability will also promote the growth of very large hail over 2 inches in diameter and wouldn't be surprised to see a few reports of softball sized hail either. Those in the threatened area will need to once again heed these warnings these will be fast moving!! I'll be posting updates as they occur on our facebook page. Congratulations to Zack also who was able to get a tornado yesterday even though it was brief. Unfortunately I wont be able to chase today.

Live Blog!! High Risk!! Violent Tornadoes Probable Today

2011-05-24T08:22:00.020-05:00

UPDATE: 7:32 PM CDT 5/24/11
Just a quick update that the isolated supercells that produced large violent tornadoes have finnally congealed into a line segment from Okfuskee County north to Washington county. These still show some characteristics of supercells but the rotation is not nearly as intense as what it has been but still rotating so the threat for tornadoes while it's still there is not nearly as big as it was earlier. Theres also some thunderstorms going on in the southern sections of the state where tornado warnings are in effect. Anywhere along a line from Ardmore to Pawnee and westword your threat is gone tonight. So with the threat for tornadoes diminishing somewhat and the threat for wind damage increasing this will conclude the live blog for tonight. However should tornado warnings start to re-genertate even more then they are now updates will be made to our facebook page accordingly. On a sad note 9 people have died today in Oklahoma and not surprisingly the tornado that hit Joplin has been upgraded to EF-5 which isn't suprising.

UPDATE: 6:32 PM CDT 5/24/11
Debris Falling near McCloud from a large wedge tornado on the ground again.

UPDATE 5:58 PM CDT 5/24/11
Cone tornado on the ground east of Dibble!

UPDATE: 5:42 PM CDT 5/24/11
A tornado emergency has been issued for southern Oklahoma City, Moore, Norman!! PLEASE take shelter IMMEDIATLY

UPDATE: 5:03 PM CDT 5/24/11
Reports of a diesal locomotive blown over with the same storm that went by El Reno- this is an extremely dangerous and life threatening situation please take shelter even if its 1-2 counties away!! Tornado on the ground to the southwest of Chickasha!! Large tornado reported north of Chickasha

UPDATE: 4:17 PM CDT 5/24/11
LARGE violent tornado was located just west of El Reno!!

UPDATE: 3:58 PM CDT 5/24/11
Large tornado on the ground north or Watonga!!

UPDATE: 3:36 PM CDT 5/24/11
Funnel cloud reported near Eakly in Caddo County! Wedge tornado on the ground near Lookeba!

UPDATE: 3:26 PM CDT 5/24/11
Large tornado on the ground near Canton Take your tornado precautions NOW!!

UPDATE: 3:00 PM CDT 5/24/11
A wallcoud has been sighted with the supercell in Dewey County.

UPDATE 2:10PM CDT 5/24/11
Convection is rapidly developing across parts of south west and west central Oklahoma where a severe thunderstorm warning is in effect for eastern Dewey and central Custer County. Tennis Ball sized hail and 60 mph winds are likely within this thunderstorm- radar is showing rotation within this storm near state route 33. Please note I cannot get every tornado warning and severe thunderstorm warning but when I see reports coming in you will be the first to know! Severe thunderstorm warnings will be found here. Tornado warnings can be found here.

UPDATE 1:45PM CDT 5/24/11
Recent radar trends and visible satellite imagery shows development is starting to occur in western Oklahoma between Washita and Custer Counties and just to the south of Altus. Within 10-20 minutes these storms should be tornadic.

UPDATE 1:03 PM CDT 5/24/11
Tornado watch 356 has been issued from 12:50 pm till 10 tonight. Hail to 3 inches, winds to 70 mph are possible in these areas. This watch is classified as a pds watch short for particularly dangerous situation where the threat for strong/long tracked tornadoes is high.

The above image is the watch and radar. Storm initiation is likely within the next 2-3 hours.

UPDATE: 12:25 PM CDT 5/24/11
A tornado watch will be issued very shortly as the storm prediction center is watching north central Texas into western Oklahoma for storm initiation in 2-3 hours.

UPDATE: 11:38 AM CDT 5/24/11
Just a quick update- the new day 1 convective outlook is out this is one of the strongest high risks I have seen personally in a while. 60 percent hatched for hail and wind- basically hatched means the threat for significant winds of greater then 75 mph and hail greater then 2. But the tornado threat is HIGHER

MAIN POST: 8:00 AM CDT 5/24/11

Good morning everyone. This is going to be a very dangerous day today as a rare high risk of severe weather today with the potential for large, long tracked and violent tornadoes.

This is the brand new tornado outlook from the folks at the storm prediction center. There's been a few changes since the last outlook the only real change I can see is the 15 hatched for tornadoes is now into the western 1/3rd of Arkansas. A very volatile airmass is expected to develop as the combination of strong surface heating aids in developing extreme amounts of instability. Instability forecasts by the RUC model is over 6000 j/kg once again as has been the case past few days. However the previous few days have not nearly had as much shear as is forecasted also. Below is the 500 mb heights/wind.

This is very impressive. You can clearly see the diffluant flow. Then the 90 knot jet max rounding the base of the shortwave that's going to aid in the development of very strong shear. What really worries me is the 0-3 km storm relative helicity values near the Oklahoma City Metro area which values are showing at over 550 m2^s2 which you can combine that with extreme instability values over 6000 j/kg you end up with energy helicity index values well over 12 which is just extreme because we really look for values above 1 for the small potential for tornadoes but when its over 12 your in trouble. Models are forecasting development right around the 4-5 pm time frame along the dryline which is dangerous because school is starting to get out which should be cancelled in high risk days IMO. With the presence of extreme instability, strong shear, strong low level shear thunderstorms that start to develop with rapidly become supercellular with extremely large hail, and destructive winds of 75-90 mph and strong to violent tornadoes. Later on in the night these supercell thunderstorms should eventually evolve into a bow echo with an enhanced wind damage potential with a few tornadoes and large hail possible. OSN WILL be chasing this event today with a target of Stillwater. This is the beginning of a live blog with updates later on in the day as storms start to fire up. Please heed these warnings!!

Significant Tornado Outbreak Likely Tomorrow!

2011-05-23T22:48:00.002-05:00

Those who think this has been a quiet severe weather season for the southern plains may not think the same after tomorrow. It is becoming increasingly likely that a major tornado outbreak will unfold across Kansas and Oklahoma tomorrow afternoon and evening as a vertically stacked, negatively tilted mid level cyclone barrels through the central plains spreading a 70-80 knot jet streak over a buoyant warm sector.

Above shows the intense shortwave with closed 500mb low and classic negative tilt with 70-80knot jet streak rounding the base into the southern plains. Troughs like this are usually big severe weather makers and tomorrow will be no exception.

Another thing we like to look at, especially when determining tornado potential, is the 850's or low level shear. This afternoon's GFS model continues to depict plentiful low level and deep layer shear on the order of 40-50knots. The southerly component to the low levels with the southwesterly component to the upper levels creates turning with height which is needed for rotating supercells. This will be the case tomorrow.

As has been the case the past several days, intense surface heating and a very moist boundary layer will yield extreme instability with MLCAPEs exceeding 4000jk/g ahead of the dryline by late afternoon/early evening.

Tomorrow has the looks of a classic plains tornado outbreak with the favorable timing of an intense jet streak overspreading a very unstable warm sector by peak heating. Supercells will likely initiate along the dryline which should end up somewhere near or just west of I-35 by early evening and pose an attendant threat for huge hail and tornadoes as they move east into central and eastern Oklahoma. Large clockwised curved hodographs and 0-1km helicity values between 300-400m^2s^-2 suggest that strong tornadoes are possible as well with dominant supercells. Given the expected coverage of storms and favorable conditions for tornadoes a high risk has been placed from I-35 to the north and east. This does include Oklahoma City, Tulsa, Wichita, and the tornado ravaged city of Joplin. Residents are encouraged to pay close attention to the weather tomorrow and be prepared to seek shelter immediately when warnings are issued. The storms we had today while significant were slow moving storms which gave plenty of lead time to people who were in the path. Tomorrow storms will be topping 50mph if not higher which will leave less time for people to react so it's very important that you are prepared for tomorrow's storms. This setup bears some resemblance to May 10th, 2010 where we had a line of fast moving supercells erupt along the dryline from southern Kansas into north Texas that produced numerous tornadoes(a few significant).

OSN will be chasing tomorrow with a preliminary target of Stillwater in north central Oklahoma. We will be providing updates on both this blog and our facebook page tomorrow so make sure you check back often!

Strong tornadoes Possible Today!!

2011-05-19T09:47:00.001-05:00

After a cap bust yesterday things are going to do a complete 360 degree turn. Everything is coming together for an outbreak of tornadoes some of them large and strong. Morning analysis shows low pressure between the Texas and Oklahoma border with a dryline extending from west central Kansas southwest into south western Texas with a warm front located on the Kansas/Oklahoma border. Along and south of the warm front its warm, moist and already unstable but at the same time also cloudy- however clouds are thinning out in north central Oklahoma lets say near Alva, OK. into parts of central and southern Oklahoma and areas further south. Surface dewpoints are very high this morning with readings well into the 60s with air temperatures in the low to mid 70s so things are already unstable. Looking at morning soundings that cape values are around 1400 j/kg with 700-500 mb lapse rates at 6.5 with a small cap and somewhat high LCL heights. Looking at the latest RUC model that things are looking quite unstable to say least as it's indicating high amounts of instability by 0z tonight with cape values well over 3000 j/kg and I think that's very plausible seeing as how there's some breaks in the clouds this early in the day. Along with the high amounts of instability that's going to be present it will also be strongly sheared with 0-3 km helicity values over 300 m2^s2 and deep layer shear at generally between 35 to 50 knots... however the one area that I am very concerned about is south central Kansas where its showing up to 60-70 knots of shear. For these reasons the spc has upped the 10 percent tornado threat and added a hatched area for the potential for strong to damaging tornadoes .

By later on today little in the way of capping is being shown and the rapid refresh model is showing intense supercells to say the very least.

This is roughly around 5ish and by 7 pm things really going nuts and wow to say the least!!

Any one of these supercells with have the potential to put down large tornadoes especially as low level wind flow really ramps up tonight. Zack is planning on chasing this severe weather episode. Stay tuned to our facebook page for frequent updates. On a side note with SOI values tanking La Nina is over and El Nino will be taking over soon if it hasn't all ready. Be safe- especially in Kansas.

Conditional But Potent Severe Potential This Evening Across Oklahoma!

2011-05-18T17:27:00.000-05:00

Tornado watch has been issued for areas generally just west of highway 281 and along and west of I-35 basically east of a Woodward to Clinton to Altus line and along and west of Ponca City to Oklahoma City and Ardmore line.

A rather sharp dryline has bulged into western Oklahoma with a warm front lifting into central Oklahoma. These boundaries are very defined on radar imagery which is usually indicative of strong surface convergence. Dew points have risen dramatically since this time yesterday afternoon with td's in the mid to upper 60's across much of central Oklahoma. Strong surface heating has lead to about 2500jk/g of MLCAPE across a narrow warm sector with backed surface flow and mid level jet streak aiding in deepening low level shear. Hodographs have become quite large and EHI values are rising past 7 in the 0-3km layer and past 3 in the 0-1km layer. As the low level jet intensifies here in a couple of hours these values will likely further increase. It's obvious by these numbers that the atmosphere is quite unstable and readily supportive of explosive supercell development. The impeding factor so far this evening has been the cap which while weakened substantially is remaining in place likely due to shortwave ridging aloft.

Radar echos are evident across southwest Oklahoma around Lawton, Walters, and Duncan. This is also in an area where a more robust cumulus field has developed along the dryline and initiation may take place very soon if further deepening commences. If an updraft is sustained, severe weather will be likely with the parameters favoring very large hail and tornadoes. Residents in central and southwestern Oklahoma need to be on the lookout this evening.

OSN is on standby and impatiently awaiting initiation. If something does develop you can rest assured we will be on it! We will also be chasing tomorrow likely in Kansas where shear will further increase and triple point develops. Stay tuned!

Non-Zero Threat for tornadoes Today!!

2011-05-18T13:14:00.000-05:00

After a pleasantly calm past couple days things are fixing to get quite bumpy to say the least. Over the past 24 hours dewpoints have increased by 10 to 15 degrees are are currently in the low to mid 60s with dewpoint depressions of 8 to 14 degrees. Dewpoint depressions are the difference of temperatures between the temperature and dewpoint- the lower the dewpoint depression the higher the humidity values. The higher dewpoint air return is in response to high pressure departing to the east, low pressure developing in the Texas Panhandle and a warm front draped right over central Oklahoma with a dryline located in western Oklahoma. Visible satellite imagery is showing clouds starting to decrease and this will help the air to destabilize. Currently MLcape values are up 500 j/kg up to the metro and of course the further south you go the more unstable the air is. Later on as the day progresses cape values of 3000 j/kg are possible directly in central Oklahoma with 2000 j/kg elsewhere this is still plenty of fuel for the fire. Now the other thing we need to watch is the wind shear. Depending on which model you look at there can be anywhere between 30 knots of shear up to 45. The lesser of the two would favor more of a multi-cell to very marginal supercell. However the low level jet will be cranking tonight to over 30 knots. Helicity values will favor rotating thunderstorms as values of over 250 m2^s2 likely. So we have the instability, the speed shear but direction shear lets take a nice little look at that. In my opinion based on what I see the I-35 corridor looks to be the ideal location where there's plenty of direction shear with surface winds out of the southeast, the low level jet at 5000 feet out of the south and then at 10 thousand feet out of the southwest. For these regions the storm prediction center has pointed out to a small tornado threat.

But on top of the tornado threat the presence of somewhat steep lapse rates just under 7 and moderate to potentially strong amounts of instability very large hail of over 2 inches will be likely with the more intense supercells. But on the other hand the hrrr model isn't showing much in the way of storms but there is 2 supercells of note. One of those supercells are in north central Oklahoma along the warm front and the other very near the metro.

So while storms look few and far between the storms that do manage to develop will pack quite a punch. There is already a chase planned for today but no target area has been acquired yet because of the isolated nature of the storms. Overall though with ample moisture steaming in, continued disturbances thunderstorm chances will be good but there will also be slow movers so locally heavy rainfall will be quite a concern especially over the weekend. The below image is from the HPC showing expected rainfall.

Active Weather Pattern Returning

2011-05-17T20:24:00.003-05:00

I'll start you off with a look at this evening's 500mb chart.

An unusually blocky pattern for this time of year continues to lead to a stagnant weather situation across the U.S. with a narrow ridge of high pressure sandwiched between two areas of low pressure, otherwise known as an omega block. This type of pattern is not one that a chaser likes to see in the middle of May when typically we are dealing with multi-day severe weather outbreaks across the plains. May so far has not lived up to its name in terms of being the climatological peak of tornado season. It's almost as if April and May switched places. Fortunately though it appears that this blocking pattern is about to begin breaking down and the next week or so could feature plenty of action in tornado alley. Let's hope so!

Analyzing the chart above. The narrow ridge of high pressure has been responsible for the beautiful stretch of weather we have seen in the southern plains featuring cool(if not cold) crisp mornings and comfortable afternoons. We certainly won't complain about this kind of weather as atypically we'd be dealing with highs nearing the 90's and thick humidity. In fact, come Summer we will be longing for the kind of days we've had so far this week. As is always the case though all good things must come to an end and we are already seeing the foreshadower of changes in the form of a southerly wind(also known as a return flow) which is pumping gulf moisture back into the southern plains. Compact low pressure system is seen to the east of the ridge which has brought a deluge to much of the northeast so far this week and will continue doing so for the next day or two as it only slowly translates east. A broad area of low pressure is organizing out west and will carve out a nice trough heading into the plains by mid-late week.

There will be a marginal risk for severe storms as early as tomorrow as a warm front lifts into Oklahoma intersecting a sharpening dryline west of I-35. Upper level support will not be great tomorrow but enough shear and convergence will exist for the possibility of isolated high based supercells tomorrow across central and south central Oklahoma. Increasing low level jet and curved hodographs will favor a non-zero tornado threat if storms can become rooted to the boundary layer. There's a possibility of a local chase as early as tomorrow but I'm using a wait and see approach for now. Bringing us to the chart above displaying a high amplitude trough slowly bearing down on the plains. The past few runs of the GFS and NAM have shown a more neutral-positive tilt to the trough as opposed to negative in successive runs along with a slower eastward progression. This to me makes sense given the downstream blocking however they almost appear a little too slow given the amplitude of the pattern. Regardless, increasing southwesterly shear aloft will overspread a sharpening dryline Thursday with plentiful moisture and instability in place across the warm sector.

Given that is is May, I typically would not be all that impressed with 2500-2750jk/g MLCAPE but this will be more than sufficient for supercells along the dryline Thursday afternoon. This afternoon's NAM was not nearly as aggressive with instability possibly signifying the presence of widespread cloud cover and precipitation early on. There does not appear to be any sort of lead impulse to impede destabilization unlike the last setup and QPF signals during 12-18z are weak so this leads me to believe that there will be an abundance of gulf stratus. This cloud cover is expected to break up enough to allow sufficient heating/instability to develop along the dryline for surface based convection during the afternoon/evening. The low level jet will crank by evening with increasingly large and clockwise curved hodographs contributing to a substantial tornado threat.

For now SPC has left us with a fairly conservative slight risk for severe storms on Thursday but I anticipate higher probabilities in their next outlook likely across north central Oklahoma and south central Kansas. We will definitely be out and about on Thursday which is looking more and more like an active severe weather day. Hopefully this will be the case this time.

Said system will continue progressing to the ENE on Friday with shear further increasing in the upper levels and with dryline hanging up to the west the threat for severe weather will likely persist and possibly intensify across the plains on Friday. However what happens on Thursday will likely impact the destabilization process for Friday so again a wait and see approach.

Models are fairly enthusiastic about bringing in another system by late weekend/early next week with dryline remaining west of I-35 and gulf moisture readily available. This is certainly an encouraging thing to see as after all it is the 17th of May and time is beginning to run out on our chase season.... at least down in the southern plains. We may need to make some trips up north this June.

Stormy Times Ahead!

2011-05-16T12:58:00.000-05:00

From one extreme to the other it goes from March back to May. Gotta love the weather like that! Current surface analysis shows a stationary front back near Midland, Texas with high pressure over west central Oklahoma. Over the next 48 hours high pressure will slip on back to the east and that will allow for the stationary front to move the northeast. Just beyond that time frame a warm, moist and unstable atmosphere should reside once again across the region. By this time frame surface dewpoints well into the 60s are anticipated along with a dryline located in west Texas. By Wednesday the dryline should be located in Western Oklahoma at the same time a "La Junta Low" develops. Basically a La Junta Low is low pressure that develops in La Junta, Colorado.

Of particular interest in this area is the jet max of 80 knots rounding the base of this cutoff low- this is roughly 60 hours out or by Wednesday night. This is where things get pretty complicated. High moisture content will be in the air with precipital water values over 1.5 inches and at the same time the airmass will be partially capped during the morning but at the same time that's not to say there wont be any morning convection but the again and what cap there is in the morning is all but gone by early afternoon hours. The problem also is there will be moderate amounts of instability to play with and theres plenty of wind shear to support organized thunderstorms include supercell thunderstorms. There will also be moderate amounts of helicity or the potential for rotating winds so isolated tornadoes cannot be ruled out as convective temperatures are not that high. However at the same time we cannot say for certain which days will have the better potential for severe weather then others but we will watch it like a hawk!

The last part of the forecast is also quite tricky. Who will receive the highest rainfall totals? Once again it will be hard to determine any small scale feature such as outflow boundary from leftover morning thunderstorms will locally enhance convective potential and thunderstorm training. across the same areas. This particular map is overall showing how much rainfall should happen I had it go out to 156 hours it's showing much needed rainfall across the area but what concerns me is it's underdoing the amounts. For example we had a heck of rainfall for 3 days and the gfs was indicating over 4-5 inches of rain back in late April/ early May and we ended up doubled that. In fact at my house we picked up over 13 inches of rain!!. So we will defiantly be watching it. In the meantime enjoy this nice weather as it promises to be quite stormy to say the least over the later half of the week.

When May Becomes March...

2011-05-14T13:00:00.000-05:00

Waking up this morning to temperatures in the 40's in mid May is definitely a slap in the face. Temperatures in the far west Oklahoma Panhandle actually hit the freezing mark. Shortly after noon temperatures struggle to make it past 60 in many areas and it's unlikely we'll make it to even 70 by peak heating. A continental cold front following Wednesday's system has scoured out the hot and humid air mass of earlier this week and replaced it with a cool crisp one. Temperatures will run 5-15 degrees or so below average through Monday before we begin to see a more substantial moderation in temperatures. The most noticeable chill will be at night when temperatures will be in the 40's.... jacket weather for sure.

Northwesterly flow aloft can be seen dominating much of the plains and draining chilly(and dry) air from Canada into the central and southern U.S. Notice the offshore flow across the Gulf of Mexico likely shoving the more robust tropical moisture well to our south. The next system can already be seen digging into the western U.S. with height rises in between(these height rises will eventually shift east into the plains by early next week which will help moderate our temperatures). One other thing I'd like to point out is notice the blocking across Canada. This is evident of a negative AO(Arctic Oscillation) and high latitude blocking in May can only mean one thing - below average temperatures across a large part of the U.S. The effects of the AO are most profound during the winter months which usually contribute to the build up and draining of polar air masses into the U.S. but during the late spring and summer an AO typically alludes to drier and cooler air from the north to the south via a northwesterly flow regime. A pattern NOT favorable for severe weather.

Fast forwarding to mid week of next week. That system you see digging into the western U.S. will carve out a nice trough of closed low pressure spreading increasing southwesterly shear across the southern and central plains. Similar to what happened Wednesday, the chances for widespread precipitation including the risk for severe storms will undoubtedly increase. My only concern regarding the potential for a more robust severe weather threat is the possibility of yet another weakly capped environment leading to morning convection which would likely inhibit convective potential along the dryline during the afternoon.... much like what happened this past Wednesday when panhandle convection stabilized the boundary layer. Given that it is May after all, the increased amounts of shear and instability will likely produce some severe weather likely in the form of hail/wind. There is still quite a bit of uncertainty regarding the evolution of this system so things are likely to change between now and next Thursday.

Tornadoes Today!!

2011-05-11T11:50:00.000-05:00

Good morning everyone. Hope everyone has had a good night sleep cause today could be quite the roller-coaster ride as an inverted low with an associated dryline and cold front move threw the region.Morning soundings from Oklahoma City already show an unstable airmass with cape values of 1703 j/kg with storm relative helicitys at 390 m2^s2^ on top of that it's also uncapped and as a consequence showers and thunderstorms have developed across the region. Looking at the lower level wind barbs they still show that twisting and turning with a surface southeast wind , south winds at 900-800 MB and southwest at 700 MB. Some of the storms that have developed have became severe with large hail reported but later today as storms become more rooted in the boundary layer tornadoes will be quite likely with a few strong tornadoes possible. Until them extensive cloud cover associated with these ongoing thunderstorms and for now at least that's going to act to keep the air from getting even more unstable then it already is. Despite the ongoing cloud cover morning model runs indicate that ML Capes of over 3000 j/kg will be possible. Zack will be targeting the triple point today near the Oklahoma/Kansas border is. Depending on convective trends and if things get out of control a live blog will become possible- but until that determination is made stay tuned to our facebook page!!

Tornadoes Return To The Plains Tomorrow!

2011-05-10T23:20:00.004-05:00

A powerful inverted mid level trough with closed 500mb low will bring the first significant severe weather outbreak of the plains season to much of Kansas and Oklahoma tomorrow. A textbook dryline setup will be in place by tomorrow evening with an increasingly sheared warm sector characterized by rich low level moisture and moderate instability with at least 2500-3500jk/g MLCAPE east of the dryline. As height falls spread across the dryline along with the approach of cold mid level temperatures, supercells are expected to initiate by mid-late afternoon from a triple point located in northwest Kansas and possibly as far south as western north Texas. Given backed low level flow and plenty of undirectional shear tornadoes are likely with initial supercells tomorrow afternoon/evening along with a very large hail threat.

A few of the convective models show strong QPF signals tomorrow morning with showers and thunderstorms expected to develop associated with the low level jet across eastern Oklahoma. How unstable the environment can become tomorrow afternoon/evening will depend on the evolution of tomorrow morning's cloud cover/convection. Nonetheless, sufficient instability should develop in at least a narrow corridor east of the dryline tomorrow afternoon yielding an increasing severe potential. The SPC has issued a day two moderate risk from north central Kansas into south central Oklahoma for tomorrow. OSN will be chasing tomorrow possibly near the surface low near the KS/OK border. There will be a new post early tomorrow morning with an update on our status and Donny will be here to keep everyone updated throughout the day so stay tuned! Tomorrow is going to be one of those days where you would want to stay weather aware.

Severe Weather Outbreak tommorow!!

2011-05-10T14:04:00.000-05:00

Before I begin severe storms mainly in the form of large hail has been developing Much to our delight a moderate risk for severe weather has been issued across the region but there are still a few things that need to be worked out. Take for example the 0-3 km helicity with the low pressure is forecasted to be around 150 m2^s2^ according the nam and gfs and with low pressure that close values should be higher especially since the nam is upping the low level jet to 30 plus knots at 7 pm tomorrow as compared to yesterdays run that had it at 10-15 knots and then increasing over the next few hours so IMO there's still feedback issues. One thing that could get this from getting to out of control is that some models are forecasting convection developing along the dryline by 1 pm as the cap is forecasted to to weaker then what it has been over the past couple days. Even if the instability is less then forecasted the combination of 35-45 knots of shear, 0-3 km helicitys of 100-150 and the instability that does develop will allow these storms to become supecellular- with steep lapse rates over 7 and 500 mb temperatures of -10c to -15c will make it easy for hail to form- very large hail at that probably tennis ball sized or higher will be common with the stronger cores. Along with that there's good twisting in the lower levels with southeast at the surface, south at 850 or 5,000 feet and southwest at 700 mb or 10,000 feet so tornadoes will also be possible as convective temperatures will also be quite lower also. Not only will supercell thunderstorms be possible but splitting supercells are also quite likely along with line segments. With the line segments there will be enhanced chances of damaging winds of 60-75 mph possible. Stay Tuned
tomorow!!!

Severe Weather Outbreak Coming!!

2011-05-09T09:34:00.000-05:00

Well, well what a surprise yesterday as the cap broke yesterday and more storms developed then first expected but also as expected it quickly turned severe but there just wasn't enough umph to sustain them as there just wasn't enough upper level support. However 1 inch hail did fall in Lawton, Oklahoma along with 1/2 inch hail just north of Mustang. We may actually see another repeat performance as the dryline that was in the vicinity has moved back west. Currently the dryline is back into western Oklahoma and as the day progresses the dryline will start to move east. Strong instability will once again be in place as ML capes will easily climb over 3500 j/kg however unlike yesterday models indicate the cap wont be as strong as what it was it was yesterday.One question remains will these be elevated or surfaced based? Models are forecasted the convective temperature (or the temperature at what the thunderstorm can become surfaced based) is over 100 degrees but models indicate that temperatures are going to be just 5 degrees cooler then that so once again they will be slightly elevated with once again large hail and damaging winds the main threats. Now even more fun and games are forcasted for Tuesday as thunderstorms are expected to be a tad more widespread and once again the nam is forecasting the convective temperature at 99 but the gfs is forecasting it t only 91. Now the problem is the nam and the gfs also don't show as high as helicity values however giving a moist environment that may just be enough to get them to rotate. Say the nam model is correct then the thunderstorms that go up tomorrow will be slightly elevated with wind and hail the main threat and if the gfs model is correct not only will these thunderstorms have the potential to be surfaced based with large hail and damaging winds a tornado threat would also exist as a 30-40 knot low level jet ensues- plus winds are changing with height with a south/southeast wind at the surface, a southerly wind at 850 mb or 5000 feet and southwest at 700 mb or roughly 10,000 feet. Now this where things become a tad bit more concerning for Wednesday. Everything is shaping up to be an outbreak of severe thunderstorms capable of very large hail, damaging winds and tornadoes-some of them strong. The nam model is hinting at isolated storms going up around 7 pm and the isolated storms are the ones we need to worry about- however the low level jet will be only at 15-20 knots which is marginal for tornadic storms however by 9 pm it increases to over 40 knots and and further increases to 60 knots by midnight to 1 am. Along with the low level jet strengthening the helicity or potential for rotating winds will be increasing also along with the instability. The gfs model however is forecasting the low level jet to already be between 30-40 knots by 7 pm and I am tend to agree with the gfs as it has been more consistant then the nam and was to dry for yesterday. Zack is planning to chase both tomorrow and Wednesday!! Stay tuned!!

Plains To Become Focal Point For Severe Weather Next Week

2011-05-06T14:47:00.009-05:00

It's obvious that the hot spot for tornadoes so far this spring has been anywhere but "Tornado Alley". In fact many places west of I-35 have yet to see any action this spring and this may be changing very soon. It would appear that we will be shifting the focus for severe weather from the southeast to the southern plains next week which could include multiple back to back days of severe thunderstorm activity in more chaser friendly terrain. I'd say it's about time too.

The graphic above shows the 500mb chart valid Sunday evening. We can clearly see the pattern amplifying with a trough digging into the western U.S. and ridging amplifying across the central U.S. This is a classic trough-ridge pattern that a chaser like myself likes to see when looking for a trigger for any severe weather in the future.

Southerly return flow already underway this afternoon will have advected rich low level moisture with 60-70+ dew points ahead of a sharpening dryline across western Oklahoma by Sunday evening. Strong surface heating combined with the low level moisture will have yielded strong instability and typically this would raise the bar for severe weather. However, at the same time increasing southwesterly flow and ridging aloft will serve as negative factors to Sunday's severe potential. Southwesterly flow tends to warm mid levels substantially due to dry/warm air being transported from the desert southwest. This results in what meteorologists refer to as a "cap" which those familiar with this blog should know by now the cap acts to preclude thunderstorm initiation until a force such as a trough or cold front with cooler mid levels can break it down. The trough by Sunday evening will be in its developing stages and quite far away and so there will be relatively little forcing available to break the capping inversion. Furthermore the ridging I talked about will create a sinking motion or subsidence which discourages warm moist air from rising and creating cumulus clouds the initial stages of thunderstorms. At the same time though thermodynamic profiles and relatively large hodographs are evidential to the severe potential if a storm can get going. A weak ripple or wave of energy in the jet stream passing underneath the ridge COULD be enough to allow isolated supercells to break the cap and if this occurs then severe weather is a sure bet. Relatively high dew point spreads though may limit the tornado potential, especially if the NAM has its way and I'm not completely sold on a chase on Sunday just yet.

By Monday a large scale trough will have evolved out west with a high amplitude ridge building east of the plains. Southwesterly flow aloft will have become established transporting pieces of energy from the base of the parent trough into the central/southern plains. Due to the slow nature of the system the dryline will hang itself up to the west of I-35 moving very little between Sunday and Wednesday. Severe weather will again be possible on Monday but the cap further increases and so confidence in storm initiation is even lower. What is for certain though is that temperatures will really be on the increase with highs likely to be well into the 90's and even a few 100's are possible across western north Texas and parts of southwest Oklahoma. It will certainly be very summer-like with hot and humid conditions encroaching much of the southern and central U.S. next week.

By Tuesday-Wednesday the trough will begin to eject into the plains with the system itself traversing the area on Wednesday. Shear will further increase and the mid levels will cool somewhat leading to an enhanced probability of severe weather both Tuesday and especially on Wednesday. Low level shear profiles and instability will be such that supercells are likely capable of very large hail and tornadoes. Wednesday has the potential to be a severe weather outbreak with a textbook dryline setup across the southern and central plains. The SPC has highlighted both days as having a 30% or greater probability for severe weather. We will likely be chasing multiple days next week so stay tuned to our blog for updates! Hopefully this is a prelude of things to come this month!

Multi-day Severe Weather Event Next Week(?)

2011-05-04T22:13:00.004-05:00

May is here and those of us in the southern plains know all too well that May is typically the peak of our tornado season. It has been a relatively quiet severe weather season for the plains(especially west of I-35) this year so far but there are indications that this may begin to change as early as this weekend.

The long range GFS and ECMWF models agree that a dryline will become established to our west this weekend as southerly return flow advects deep low level gulf moisture into the plains. Strong instability will be in place ahead of the dryline with the GFS in particular displaying 4000jk/g+ MLCAPE over much of the central/southern plains. Sunday-Wednesday is the timeframe that we are watching as a long wave trough takes shape to our west bringing increasing shear across a buoyant warm sector with waffling dryline across the southern plains. Severe weather appears increasingly likely over a span of multiple days though the degree of impact is highly dependent on how things come together(i.e. capping inversion, orientation, positioning, and timing of trough, etc. ). In any case we definitely have our eyes set on next week for the possibility of some chasing. I need to get out there again!

April 26th Chase- Stuttgart, Arkansas

2011-04-29T12:28:00.001-05:00

A couple days before this was to take place storm chasers Jake Riley, Nate Riley and myself all decided this event was worth chasing. We all agreed as a target to start off would be Stuttgart, Ar then we decided on Pine Bluff before deciding to head down to Texarkana going down I-30 where we grabbed some lunch at Burger King in Hot Springs then ventured into Texas all while dealing with some light rain. 10-15 miles into Texas the light rain blossemed into strong thunderstorms and quickly became severe. After realizing we couldn't make a play on the storm in Texas we decided to head back into Arkansas. Unfortuantly we were not able to catch them untill we were nearing the Mississippi border. After nearly 9 hours on the road we decided to call the chase that is untill 2 supercell thunderstorms became severe warned near Stuttgart and we decided to try to make one last play on these newly severe warned cells. We had a funnel cloud develop right over us and it was a dousy but we couldn't see it no more then after the last part of the video we had a brief 30 second spinnup but due to it being dark I wasn't able to get it on film. But we were able to get this footage from our original target in Stuttgart, Arkansas near highway 63. So after the brief tornado we were pretty happy and we were on our way back to I-40 and then we ran into problems- more thunderstorms became severe and we were trying to pull over caught strong gust of wind and hydroplaned into a ditch- fortunantly for us the injuries were minor. After the EMT got there we were told had we not been wearing our seatbelts we would have gone threw the windshield- so it don't matter if your chasing, going to the store- anything can happen so always buckle up. Also one last thing TURN AROUND DON'T DROWN!

The Calm After the Storm

2011-04-28T14:07:00.000-05:00

My apologies for not making a blog yesterday something came up. Loss of life and property has been happening over the past couple days as a pesky front stalled across the region. With high amounts of shear and instability present the air became very favorable for dangerous supercell thunderstorms- in fact I looked at the tornado probability for yesterday the spc folks has it at 45 percent- I have never seen this happen- it didn't happen with 2007 in Greensburg, May 3rd '99 , May 10th last year this is absolutely unprecedented. This event may have very well out did the '74 super outbreak!! That's not the most damning part about it either- these were not normal tornadic storms that but down brief tornadoes- these were massive tornadoes take for example the one from Vilonia , Arkansas was up to a mile wide and was on the ground for 51.1 miles- but compared to some of the tornadoes that occurred yesterday this could easily out done. Storm surveys are going to be done over Mississippi and Alabama in places that were hard hit like Huntsville and Birmingham. There was also a place that had tornado sirens actually blown down and they got hit a second time. It's times like these that makes me angry because you can spend 40 dollars on booze and get a buzz or you can spend just a tad more, get rechargeable batteries, a battery charger and a noaa weather radio so you will know whats coming and when it's coming if you lose power. I will also say this though the fact that these tornadoes went threw densely populated areas and then the size of the tornadoes and how violent they were loss of life would have probably happened anyways and it's very sad that this has happened. The last check I did that over 251 people have lost there life and up to 165 tornadoes touched down- this is way overdone that if you look at the plotted map most of these tornadoes were the same one that got reported several times and again given the extent of the damage it wouldn't surprise me if some of these tornadoes were rated EF-4 to EF-5. Unfortunately however our friends on the east coast have a chance for a few tornadoes and damaging winds but the good news is that it doesn't look as nasty as what it was. After this system moves offshore we will have a few quiet days before more thunderstorms are possible. Sunday as a cold front moves threw region looks to be another chance for severe weather but not to impressing. Looking at some the parameters there will be some decent instability to play with ML capes over 1000 j/kg and shear is supporting of supercell thunderstorms but the low level jet isn't really cranking so not much of a tornado threat on top of that the wind fields are going to be uni-directional- inotherwords not much twisting and turning with height so the real threat is going to mainly be large hail and damaging winds. The best chance for severe weather will be in southern Oklahoma and northeast Texas maybe southern 1/2 of Arkansas. After that more calm weather looks promising. Stay tuned as I will be posting my chase log from Tuesday soon!!

Dangerous Situation In Arkansas This Evening

2011-04-26T16:38:00.005-05:00

A rare high risk for severe weather has been issued from the Arklatex region into the lower Mississippi river valley in anticipation of a dangerous outbreak of severe storms and tornadoes this evening and tonight. Much of the same areas in today's high risk have already been raked by damaging tornadoes yesterday including a deadly tornado that flattened parts of Vilonia, AR leaving 4 dead and many more injured/missing. Today's tornado potential will be escalated by a strong low level jet developing this evening across the warm sector characterized by deep low level moisture and strong instability. Tornadic supercells are already underway across parts of northeast Texas into central and southern Arkansas where a Particularly Dangerous Situation(PDS) tornado watch is currently in effect

In addition to the tornado threat, historic flooding of the Mississippi and other areas lakes/rivers is occurring from the extreme rains attributed to this past weekend's thunderstorms and the expectation of more heavy rain tonight.

Donny Cook and Jake Riley are out chasing this afternoon/evening over south central Arkansas and you can get the latest on their position and status on our facebook page here.

High Risk!!!!

2011-04-26T08:12:00.000-05:00

As anticipated yesterday a high risk for severe weather has been issued for today as a very volatile airmass is expected to develop later today. Visible satellite imagery is already showing sunny to partly cloudy skies in the high risk area and that's going to allow for temperatures to rise nicely but there's a catch. At the same time a warm front is going to move north across the region and that's going to allow surface dewpoints to really climb into the upper 60s to low 70s.The high dewpoint air combined with steep lapse rates over 7 will allow for high amounts of instability to develop with ML capes expected over 3000 j/kg- that combined with a high amount of wind shear already in place will create a very volatile airmass. As the warm front moves north and a strong wave develops across the area not only will deep layer shear increase but low level wind shear will also increase. Later in the day a dryline is expected to move into this warm moist and strongly unstable airmass and the result is obvious dangerous supercell thunderstorms capable of producing extremely large hail- likely larger then baseballs, destructive winds over 75 mph and the kind of tornadoes that can destroy towns and stay on the ground for quite a long time- likely cyclic supercells. As these supercell thunderstorms start to congeal a derecho is likely to form with embedded supercell thunderstorms with widespread damaging winds and a few tornadoes. My chase partner Jake and I have changed our target from Pine Bluff, Arkansas to Texarkana and play the dryline. Zack will be updating time to time as I give updates and a live blog will probably needed so stay tuned- heed these warnings they mean business.

Radar Images From Arkansas This Evening.

2011-04-25T20:54:00.008-05:00

EDIT 9:30pm CDT - Reports coming from Vilonia are not good. It appears that the western and northern sides of the city sustained heavy damage if not a direct hit. Reports of pavement scoured and cars blown off the road.

Radar images saved from tonight's severe weather outbreak in Arkansas show a nasty supercell with tornado moving very near the town of Vilonia, AR. Of interest is the "debris ball" associated with the hook echo. Usually the "debris ball" is indicative of debris being lifted aloft into the atmosphere and the radar beams reflecting off the debris resulting in a concentrated area of high reflectivity on radar(notice the high dbzs in the center of the hook). Usually a signature like this represents a violent and damaging tornado and a tornado emergency was issued for Vilonia at 7:24pm CDT. Tornado emergencies are rare issuances and are typically issued when widespread damage of a city is imminent. Damage has been reported in the Vilonia area but I do not have a whole lot of details on the situation as of now.

A Moderate risk remains in place for much of the same areas hit by tonights severe weather for tomorrow. Donny Cook will be chasing tomorrow's setup which could be more volatile than today as warm front situates itself in central parts of the state and a secondary vort max ejects from the southern plains resulting in a highly sheared warm sector. Preliminary target for tomorrow is Pine Bluff, AR. We will be providing updates on tomorrow's chase on facebook so make sure you "like" us to stay up to date!

Also check out video from Friday's storm chase in east central Oklahoma below! Tim, Kevin, and I chased several tornadic supercells featuring wall clouds and large hail. At one point we were two miles away from a rain wrapped tornado near Welty, OK.

Dangerous Day for Tornadoes and Flooding

2011-04-25T11:43:00.001-05:00

Last night a nocturnal MCS developed and has been steadily moving east at 30-40 mph and had been producing torrential rainfall as its moved east. Over the past couple hours it has been steadily intensifying with wind damage becoming a concern. Behind this MCS cloudy skies have been the rule however visible satellite images are indicating there are some breaks in the clouds in parts of western Arkansas into southern Arkansas into northeast Texas. This is allowing for some significant heating to take place where ML cape values are currently reading from 1000 j/kg in the southern 1/3rd of Arkansas up to 3000 j/kg into northeast Texas including the Dallas metroplex. In addition to this unstable airmas it's also fairly sheared with 0-3 km helicity values are between 300 and 500 m2^ s2^ which is more then sufficient for supercell thunderstorms to rotate with the potential for damaging winds, very large hail and tornadoes. With the aforementioned instability, shear and moisture in place with the dewpoints in the upper 60s as long as they remain discrete will have no problem putting down very large tornadoes. A tornado watch recently got issued- while it is not classified as a particularly dangerous situation tornado watch its an upped up version of a tornado watch with the potential for 2 or more tornadoes at 60 percent and the chance for 1 or more strong tornadoes at 40 percent so these storms will defiantly mean business. While thunderstorms are ongoing at the present time were expected a warm front to develop in southern Arkansas within the next 2-3 hours and this is going to really charge up the airmass as it moves even more warm and humid air. It's these storms that form south of the warm front that we really have to watch. On top of the severe weather threat we have another threat- flash flooding. Several areas have received upwards of 5 inches of rain with upwards of 10 inches of rain in portions of northeast Arkansas and southeast Missouri. The combination of highly moist airmass, a slow moving front and thunderstorms that train over the same areas will make flash flooding likely. For this reason numerous flash flood watches are out- in fact there is one particular flash flood watch that I would like to point out- neither Zack or I have seen this kind of flash flood watch wording "...VERY HEAVY RAINFALL OVER THE NEXT COUPLE OF DAYS WILL LIKELY LEAD TO SIGNIFICANT...WIDESPREAD FLASH FLOODING......THIS IS A PARTICULARLY DANGEROUS SITUATION...This goes to show you these thunderstorms mean business and rainfall rates of 2-3 inches per hour are going to be likely in the heaviest of thunderstorms. Stay tuned to our facebook page for updates and keep safe!!

Monday and Tuesday severe weather outbreak!!!

2011-04-24T14:04:00.001-05:00

First and foremost on behalf of OSN happy Easter!! It's been a wet morning and early afternoon in central Oklahoma where much needed rain and thunderstorms are developing behind a cold front. Since there behind the front if thunderstorms turned severe in Oklahoma large hail would be the main threat. Today's going to feature some severe weather but what's going to happen today is a prelude of what's forecasted Monday and Tuesday. Today an MCS is in western Arkansas and generally moving the east/northeast about 30 mph ahead of slow moving cold front. These do have supercell characteristics. ML capes of 2000 j/kg, low level helicitys of greater then 200, and low level shear of 25-30 knots will support isolated tornadoes and wind damage mainly in northern and parts of central Arkansas as there is a tornado watch in effect until 7pm tonight. 850-500 MB lapse rates of 7 plus will also support a large threat. After today things go downhill for the worst.

This is the day 2 outlook. Note the moderate risk in much of Arkansas and southern Missouri. Showers and thunderstorms are expected to be ongoing threw the beginning of Monday in Oklahoma and some of them will likely be severe with large hail and isolated wind damage with a developing surface low/cold front. As the day progresses with dewpoints in the upper 60s to low 70s when coupled with upper 70s to low to 80s should allow ML cape values over 2000 j/kg. Steep mid level lapse rates would promote a large hail threat with significant hail threat. There is a high chance for supercell thunderstorms to put down large tornadoes as the combination of moderate instability and 0-3 km helicitys with high dewpoint air mixing up. I would not be surprised to see a day 1 high risk issuance for Monday or Tuesday for that matter. The day 3 outlook begins with a slight risk of severe weather with a 30 percent hatched area into Arkansas, western Tennessee, and northwest Mississippi. What could make this day more dangerous then Monday is that this is a stronger low/shortwave. The nam model isn't as aggressive with the instability while the gfs is showing once again greater then 2000 j/kg ML cape and these numbers could be underdone or overdone depending on how much sunshine can be realized. However one thing that both models show is 50-60 knot shear which supports supercell thunderstorms. Nam shows a weak low level jet but intensifying later on while the gfs has 30-40 knot low level jet by Tuesday night. So there is still some convective feedback issues going on but over the next 24-36 hours these issues should be worked out. Stayed tune as this promises to be a very dangerous 2 days. Depending on how things work out on tuesday I will be chasing.

Let the Mayhem begin!!

2011-04-22T12:09:00.000-05:00

First I wanted to say that note the new storm prediction center convective outlook it looks much much better to me then what it previously has. Good late morning everyone I hope y'all have enjoyed the somewhat nice weather lately cause were heading into a severe weather period where every 2-3 days were going to be having to deal with severe weather including tornadoes, large hail and damaging winds. It is however impossible to pin down on what does look better then others. So that is what gets us to the new day convective outlook. The previous outlook had a slight risk but the spc boys have decided to upgrade parts of the area to moderate risk for mainly east of I-35. I have no reason to disagree with this. The RUC model is being quite aggressive with instability values with forecasted CAPE as high as 6000 j/kg in south central Oklahoma with the latest mesoanalysis pointing out at 3000 plus MU cape. A warm front is located north of I-40 in central Arkansas and extends to the northwest of were it attaches to a deepening low pressure area north of Oklahoma with a cold front is located in the Oklahoma panhandle with a dryline noted in southwest Oklahoma. These should all merge together as a triple point near Oklahoma City. South of the warm front dewpoints are in the low to mid 60's with values in the 70's in southern Arkansas. By 2-3 pm showers and thunderstorms are expected to develop - according to the hrrr model a supercell should start to erupt in south central Oklahoma and then 2-3 hours later Oklahoma threw Missouri will light up with thunderstorms. The amount of instability combined with 50-60 knots of shear would support supercell thunderstorms. Main threats with be damaging winds of 65-75 mph with large hail likely also in the strongest core. Steep 850mb to 500 mb lapse rates of 7.5 to 8 combined with low freezing levels will make it easy also for significant hail greater then 2 inches possible. The tornado threat is going to be difficult to say the least. The high helicity values will be located in northeast Oklahoma into northwest Arkansas and Missouri closer to the low again- were the best juxtaposition of shear/helicity and instability will be maximized so that is where the best tornado threat would be. However into central Oklahoma there will be high instability but the helicity will be lesser but still supportive of a few tornadoes- but the hodrograph specifically out of Oklahoma City is showing me there is some curvature but linear also so there should be initially supercell thunderstorms- some splitting and eventually transitioning over to a squall line- say about 250-300 miles to the northeast in southwest Missouri its more curved so the higher tornado potential. Eventually the a mcs should take over with embedded supercell thunderstorms will push to the east/southeast tonight and during the overnight hours with an enhanced wind damage threat with a chance for a tornado or two. Stay tuned!!

FINALLY The Pattern I've Been Waiting For!

2011-04-20T20:59:00.005-05:00

For most of the southern plains this Spring has been bone dry. It has been over a month since Oklahoma city has received any measurable precipitation and even so precipitation for the last 6 months has been a little over 2". It's no wonder why we are on the verge of one of the worst droughts since the dust bowl times and why fires have been running rampant. We are in DIRE need of rain and finally it appears that God is answering our prayers. The pattern heading into the weekend and beyond looks quite favorable for rain(some of it heavy) and severe weather for the southern plains.

We'll start with this evening. WAA(Warm Air Advection) is in the process of kicking in as warm moist air lifts up and over the cool air mass that has settled in across the area. Frontal boundary has stalled not far from the red river and will retreat north as a warm front tomorrow. The increase in lift tonight along with elevated instability and increasing mid level moisture would typically prove to be a favorable setup for widespread rain and thunderstorms. However this instability is capped which has been the case for much of the season. This mixed layer cap will weaken some tonight which should allow for the development of showers/thunderstorms with the best chances being across the south.

Tomorrow/tomorrow night we should see better chances for thunderstorms and there is a slight risk for severe weather across most of the area. This is likely for elevated hailers given moderate mixed layer cape and steep mid level lapse rates. Significant severe weather tomorrow is unlikely.

Friday could get interesting however as said warm front surges back to the south as a could front and dry line pushes east into western Oklahoma. A triple point looks likely to set up somewhere in the state Friday afternoon/evening(the GFS is not nearly as far south with the cold front as opposed to NAM) with moderate-extreme instability developing within the warm sector across central and southern Oklahoma. With increasing shear profiles and favorable thermodynamics severe weather is a sure bet on Friday and some of it could be significant.

The weekend will feature the front waffling back and forth across the area which will continue rain chances through the holiday. By Monday, high amplitude trough takes shape to our west with developing dryline setting up west of I-35. Monday has the makings of a severe weather outbreak and will need to be watched pretty closely.

With the active weather pattern shaping up some areas will end up with significant rainfall over the span of a few days which will be beneficial in our case. However with the dry ground it may take awhile for the rain to soak through and some flash flooding could result over the weekend. It is important it being a holiday weekend that you are abreast of the latest weather conditions. Stay tuned!

Derecho Likely Tonight/ Overnight

2011-04-19T08:55:00.002-05:00

Despite the already active morning we have with showers and strong to severe thunderstorms accompanying the warm front things are going to be getting much more active. The storm prediction center in Norman has expanded the moderate risk to include much of northern and central Arkansas. It would not surprise me if a high risk for severe weather was to be issued from say north Arkansas, southeast Missouri, into southern Illinois and southern Indiana. In the warm sector low clouds are hanging on and that allowed for low temperatures to hang on quite warmly but is also capping the airmass for now that is. Temperatures are nice and mild in the low to mid 70's already with dewpoints in the upper 60s to low 70's. Visible satellite image shows the low clouds already starting to break up the combination of strong southerly winds (where Wind Advisories are in effect) and plentiful sunshine with allow for near record high temperatures in the upper 80's to low 90's possible. At the same time the airmass is rapidly destabilizing. At the same time a cold front/dryline will be scooting to the east and should in east central Oklahoma by later in the day say by 4-6 pm. By then showers and thunderstorms will begin to blossom. There is window of opportunity for discrete supercell thunderstorms to form and these will have the potential to put down very large hail, damaging winds and a few tornadoes. However the greatest potential for any storm to drop tornadoes would be in northeast Missouri, southern Illinois and Indiana where the low will track- this is where the low level shear and helicity will be maximized. Within 2-3 hours of initiation with strong forcing with winds paralleling the front the storms should congeal into a qlcs (quasi linear convective system) with less of a tornado threat with enhanced threat for wind damage. However that's not to say the tornado threat is completely negligible further south. In fact the wording from the spc is suggesting a derecho which is looking more and more likely- especially across the moderate risk area where the ruc (rapid update cycle) model is forecasting a whopping 5-6000 j/kg of cape. This of course will be watched. While a live blog doesn't seem likely stay tuned to our facebook page for weather watches that will be issued threwout the later part of the day.

New Week, Same Story...

2011-04-18T20:45:00.006-05:00

241 tornadoes touched down from eastern Oklahoma to North Carolina Thursday-Saturday as a powerful spring storm system made its trek across the U.S. Unfortunately this week looks to offer little if any respite from the stormy weather pattern we have found ourselves in.

A moderate risk is already in place for tomorrow as residents in a similar area from last Thursday's severe weather only this time expanding to include much of the Ohio river valley gear up for another potential severe weather outbreak. Perhaps the difference between this past weekend and tomorrow is the fact that not only is the affected region farther to the north but the atmosphere will be "stacked" differently. In other words the directional(or low level) shear will be more veered(WSW) as opposed to backed(SSE) which depreciates the tornado threat somewhat. This also in junction with strong forcing along a stout cold front/dryline tomorrow will likely mean that storms will quickly become linear meaning more of a damaging wind/hail threat. HOWEVER any discrete supercell that forms tomorrow and there will be a narrow window of opportunity for semi-discrete storms, will likely be capable of very large hail and tornadoes given the shear parameters. It is also likely that the peak of the event tomorrow will occur during the night hours which makes this a potentially dangerous situation. Residents in the risk areas tomorrow are urged as always to stay weather aware.

For us in Oklahoma, as has been the theme thus far this year, the better chance for storms and attendant risk for severe weather will be primarily east and northeast of I-35. Dryline will leave the state divided yet again with enhanced fire weather concerns west and the possibility for severe weather east. Near record warm temperatures tomorrow, very dry vegetation, and windy conditions will make for the rapid spread of wildfires so please be cautious. We are in dire need of rain and it DOES appear by the models that the pattern COULD become favorable for a potentially significant rain event for our area this weekend into next week with the possibility of a stationary front setting up in our vicinity with disturbances riding it. Let's hope so!

Follow up links from last week's severe weather:

I wanted to post a follow up on this past week/weekend's severe weather outbreak but I just haven't had the free time to do it and because it is getting late in the game I probably won't get around to it. SO I will leave you with links with very good write ups from the corresponding national weather service offices in the affected areas.

Oklahoma Tornadoes:

Thursday's Tornado Outbreak - Tulsa, OK

Thursday's Tornado Outbreak(feat. the deadly Tushka, OK tornado) - Norman, OK

Friday's Tornado Outbreak Across Mississippi & Alabama:

Jackson, MS Write up

Birmingham, AL Write up

Saturday's Tornado Outbreak Across North Carolina:

Raleigh Tornado Survey

Raleigh, NC NWS for additional surveys

Great blog from Accuweather going in depth on the North Carolina tornadoes

Stormy Times ahead next Week

2011-04-16T12:43:00.002-05:00

All I can say is what an active 84 hours we have had from a tornado touching down in Oregon , to the damaging tornadoes in Oklahoma , the overnight severe weather in Arkansas to the damaging tornadoes in Alabama and Mississippi to the now rare high risk of severe weather in eastern North Carolina where a pds tornado watch is in effect. After a calmer Sunday things are going to get active once again as high pressure slips onto the east and allows for a nice southerly flow. However with very dry conditions it's going to take awhile for things to moisten up in Oklahoma. At the same time there's going to be 2 lows to watch- one of them is going to move to the north of the area and the 2nd on is the main one to watch. Tuesday morning surface dewpoints in the low to mid 60's should be residing as far north as northern Missouri. A stout cap of +27 c at 850 MB will hold strong throughout most of the day and early evening. While there maybe some early morning stratus clouds, a return of full sunshine is expected. By Tuesday night a warm front should be located near the Iowa/ Missouri border with low pressure in southeast Kansas and Northeast Oklahoma. A dryline should be located east of Oklahoma City with a surface cold front back into central Kansas. Dewpoints in the the low 70's as far northeast as southern Illinois will be noted. The combination of high dewpoint air and steep lapse rates will create a very volatile airmass as ML capes between 2500-3000 j/kg will reside in the warm sector. Extreme amounts of helicity (ie potential for rotating winds) with values of 0-1 km of over 300 m2*s2 will also be coincided within the warm sector along with deep layer shear of 50 plus knots will support supercell thunderstorms. By evening this unstable airmass will be weakly capped. The potential for a tornado outbreak will be quite high with the best potential for tornadoes will be in central Arkansas north word into southern Illinois. After the cold front moves threw Wednesday it will be moving back to the north as a warm front and were going to do it all over again. There is a potential this upcoming week for heavy rain and severe weather so stay tuned!!

Deadly Tornado "Flattens" Tushka, OK!

2011-04-14T21:43:00.007-05:00

EDIT 10:17pm CDT: There are now reports of two fatalities in Tushka. The Atoka high school and middle school are also reported "destroyed".

Shortly after 7:20pm CDT a large and violent tornado did significant damage to the town of Tushka, OK in Atoka county. One person has been reported dead with many more injured and/or missing. The status of the situation has been far from good.

From left to right shows the base velocity featuring a pronounced couplet at the time of the tornado as well as the base reflectivity displaying the "hook" portion of the storm.

This tornado was one of several tornadoes that have been reported across east central and eastern Oklahoma this afternoon and evening. Fortunately for Oklahoma city we managed to escape the action but only very narrowly as the dryline stalled less than 25 miles to the south and east of the area. Tornado warnings are currently ongoing for parts of far southeast Oklahoma as I type this. Severe weather will continue to shift eastward through the overnight hours eventually effecting Missouri and Arkansas where a tornado watch is also in effect. Below is a link to a short video showing the massive Tushka, OK tornado. Thoughts and prayers to all affected by tonight's storms.

http://www.ktul.com/video?autoStart=true&topVideoCatNo=default&clipId=5756838&flvUri=&partnerclipid=

Moderate Risk Today with Strong tornadoes likely!!!

2011-04-14T12:03:00.009-05:00

Today is promising to be quite active as surface dewpoints have been on the rise since last night in fact dewpoints in the low 60s are being found into Oklahoma City but that will change but how quickly is the fly in the ointment. Currently a dry-line is sitting in west central Oklahoma while low pressure is developing along the dry-line and that will in turn cause the dry-line to progress to the east while the low goes to the east/northeast. Dewpoints behind the dry-line are in the 30s and 40s while ahead of it dewpoints are in the upper 50s north of I-40 while areas near Duncan dewpoints are in the mid 60s. Later today as the dry-line moves east scattered showers and thunderstorms will develop ahead of the dry-line. The presence of strong shear and strong amounts of instability because of strong surface heating, and lapse rates of 7.5-8.5. ML cape values of 2500 j/kg are expected. All modes of severe weather will be possible from large hail probably bigger then baseballs, damaging winds of 70-90 mph and strong tornadoes will all be possible. Right now models are developing convection near the low in Kansas by 3 pm today and they will be the first storms capable of producing strong to violent tornadoes. The second area of strong tornadoes to watch for would be ahead of the dry-line. These storms should be developing between 6-7 pm and will also be capable of producing large damaging hail, strong thunderstorm winds and strong tornadoes. Once the quality of moisture return is more certain I wouldn't be surprised to see a high risk issued for northeast 1/4th of Oklahoma into Southeast Kansas and Southwest Missouri. By roughly 10pm to midnight I am expecting these supercell thunderstorms to transition into a qlcs with a lesser threat for tornadoes -though not all together negligible with an increasing threat for wind damage and hail and this will continue through the overnight hours. Again it is not entirely out of the question that isolated supercell thunderstorms to fire up ahead of the qlcs. A live blog will become necessary later one so stay tuned!!

Significant Tornado Outbreak Near & East Of I-35 Tomorrow Evening!

2011-04-13T22:31:00.005-05:00

A moderate risk of severe weather has been issued across southeast Kansas and much of eastern Oklahoma. A slight risk runs from along and north and east of I-35 extending into parts of the mid Mississippi river valley. For the first time this spring ingredients seem to be coming together for a significant severe weather outbreak including tornadoes across parts of the southern plains and very near the Oklahoma City area too. A storm system emerging from the southwest states will undergo significant amplification across the central plains with deepening surface low pressure across far northern Kansas. This powerful spring storm system will pull plume of deep low level gulf moisture into a narrow warm sector evolving just to the east of I-35 with 60-65+ degree dew points advecting as far north as southeast Kansas by 00z Friday. Strong surface heating and ample low level moisture will lead to rapid destabilization of the warm sector by mid-late afternoon with moderate-extreme instability developing east of dryline forecast to be very near or just east of I-35 by early evening.

Strong upper level forcing spreading over the dryline and a weakly capped warm sector will promote the development of scattered supercells along the dryline which may very well develop very near the Oklahoma city area(it will certainly be a close call tomorrow and in fact some of the latest runs are depicting further slowing of the system which could put I-35 in the action) and move to the north and east into a volatile air mass capable of supporting huge hail and an attendant tornado threat with any discrete supercell. By late evening a cold front will begin overtaking the dryline and with increased forcing storms will consolidate into a large squall line with a significant damaging wind threat across southeast Kansas and far eastern Oklahoma. Large low level hodographs and 0-3km shear will be supportive of some long tracked supercells capable of violent tornadoes if storms can manage to remain discrete well into the evening. It would not surprise me if parts of the moderate risk are further upgraded to a high risk by tomorrow's outlook. Residents are urged to pay close attention to weather resources tomorrow and stay abreast of the weather situation. Stay tuned!

Severe threat Ramping up again

2011-04-12T14:06:00.000-05:00

After tornadoes, very large hail and damaging winds wreaked havoc- mainly across Iowa things have calmed down markedly as high pressure is in control. It's really not that cold of a high pressure as current temperatures are in the mid to upper 70s with dew points ranging from the upper 20s in Oklahoma City to the low 40s in Arkansas. Over the next couple days high pressure will slide to the east and will allow for a nice warm southerly flow and allow surface dew points to climb to 50 to 55 as early as tomorrow afternoon and well into the 60s buy Thursday and that's where things get fairly interesting as a shortwave with an associated dry line move threw the region. Isolated showers and thunderstorms are possible ahead of the dry line. The amount of wind shear would support super cell thunderstorms with very large hail possible along with a tornado threat. The thing that could keep this from getting to out of control is a moderate capping inversion. Regarding instability the NAM model is forecasted ML capes over 2000 j/kg from east central Oklahoma north to Kansas while the GFS model isn't as aggressive it's still plenty for strong to severe thunderstorms. The storm prediction center boy's have there eyes on this region.

A 30 percent hatched area has also been added for mainly hail greater then 2 inches in diameter. There are some timing issues and where the best dynamics will be located. Overall what is expected is isolated super cell thunderstorms develop between 4-6 pm Thursday with the threat for large hail- some significant and isolated tornadoes possible and eventually congeal into an MCS with the threat for wind damage and hail becoming the main threat however, east of this MCS the air mass will not be very capped so it's entirely possible that super cell thunderstorms may for ahead of the MCS- eventually the MCS tracks eastword and with moderate instability to keep it going it will continue to produce a swath of damaging winds, large hail and a few isolated tornadoes.

Later in the weekend gulf moisture will once again return to the area bringing more thunderstorm chances but things are a little to far out to go into to much details but as it draws near of course we will keep you informed.

Supercells Exploding! Tornado Watch Issued!

2011-04-08T18:02:00.004-05:00

EDIT-9pm CDT: Chase operations did not pan out this evening as activity ended up farther north by the time chase partner was able to leave work and I did not feel it was worth the 1-2 hour drive struggling in the dark.

Several large supercells have developed across north central Oklahoma near a slow moving warm front pushing into Kansas. These storms are rapidly developing/evolving and severe weather is a guarantee for anyone in the path. Steep mid level lapse rates and MLCAPE exceeding 3500jk/g across the extent of the warm sector will favor supercells with very large hail. The tornado threat will increase later this evening for any supercell that can persist as the low level jet intensifies.

A tornado watch has been issued for much of north central and west central Oklahoma until 1am CDT Saturday as seen below.

TCU has been observed farther southwest along the dryline which continues to become better defined this evening. Isolated cells have recently been developing along the boundary across west central and southwestern Oklahoma and these too will quickly become severe if they can mature into supercells. Chase partner is currently set to get off work by 7pm this evening so we will likely be racing to our north and west within the next hour to catch up with the action. Stay tuned!

Let the 3 day outbreak begin!! Day 3 Moderate Risk!!

2011-04-08T14:01:00.000-05:00

Today is going to feature the first day of a multiple day severe weather event with Sunday being the most severe. A warm, moist and already strongly unstable air mass is in place with dew points in the upper 60s air temps in the 80s and 850-500MB lapse rates over 8 is creating ML capes between 2500 and 3500 j//kg in the region. The HRRR model is being very scary in a way to say the least with it showing a well defined super cell thunderstorm that's developing along a dry line very close to Oklahoma City and I mean very close.

If this were to occur this storm would be capable of producing large hail, damaging winds and an isolated tornado threat as 0-1 km helicitys over 150 would support low level rotation. In fact the biggest threat today is going to be hail. Even if this does occur after dark as the cap strengthens any storms that fire up today will be gone by 9-10 pm. Were going to do it all over again tomorrow with very large hail likely mainly in Iowa, SE Minnesota and western Wisconsin. After Saturday things are going downhill as there ALREADY a day 3 moderate risk out. IMO by the time the day 1 outlook for Sunday occurs the moderate risk is probably going to be expanded all the way from the northern extent of where it is now all the way down threw southeast Oklahoma threw Arkansas because if the GFS model is to believed there's going to be just as much instability in the current moderate risk area as there is going to be in the aforementioned areas. This very well may become a day 1 high risk as very rarely will you say a day 3 outlook with a moderate risk Initital thunderstorms that develop sunday will produce very large hail probably baseball sized or bigger, winds of 60-75 mph and tornadoes- some of which maybe strong/long tracked because of good boundary layer moisture and increasing shear. Now giving strong forcing along the cold front super cell thunderstorms should transition over into a serial derecho with widespread damaging winds as there is a very impressive 80-100 knot 500 MB wind at 7 pm Sunday increasing even further with a 110 knot 500 MB jet max . Keep in mind 500 MB is only 18,000 feet and if thunderstorms are able to tap into that kind of winds which is going to be fairly easy to that I wouldn't be surprised to see wind of 80 to 100 mph with the strongest thunderstorms. As always we'll keep you updated threw the event and a live blog may become necessary in areas further south if things get out control so stay tuned!!

Panorama From Kansas Chase, Saturday Chase?

2011-04-07T20:36:00.005-05:00

Sunday(4/03/11) featured a chase in east central Kansas where we documented a QLCS displaying beautiful storm structure and providing thrills with the intense lightning show and large hail. There will be a complete write up on this chase sometime this weekend. For now you can view the pictures which are available here. Pictured above left is my best shot and my second successful attempt at a panorama. The raw power and beauty of the quickly evolving storm is clearly expressed with storm chasers Marcus Diaz and Brady Kendrick featured in the foreground.

I'm already eying the next potential chase this weekend with Saturday sticking out to me as being a potentially significant severe weather day if the parameters come together just right.

The SPC chasers as I call them are all excited about Sunday which promises to be an active day across much of the Mississippi and Ohio river valleys. When I say active I mean as in one massive QLCS(quasi-linear convective system) with a significant damaging wind threat. The extreme forcing along pacific front/dryline and strongly veered jet streak favor this. I'm not saying there won't be any tornadoes as that is entirely untrue but it's not the "tornado outbreak" that some claim it to be. But hey if you like chasing a fast moving linear mess then be my guest. ;)

If you're looking for tornadoes Saturday looks to hold the best hope. I'm not jumping up and down like a giddy school girl about Saturday as there are a few things that could negatate the severe potential but the dynamics are looking very favorable for supercells. One thing that really sticks out to me is the southerly 40-50knot low level jet with 70-80knot southwesterly jet streak aloft. This creates the perfect turning with height which is needed for rotating supercells. Instability within the warm sector is also not too shabby with 2500-3500jk/g MLCAPE across west central Kansas - the area that I'm eying for the next possible chase. The NAM is a little on the dry side regarding moisture return but I believe the real say revolves around the amount of low level return flow over the next couple days with the GFS by far the most aggressive regarding dew points.

Tomorrow also could get interesting along dryline with high resolution models breaking out QPF during the evening hours. The dynamics are not incredibly strong but the thermodynamic environment and effective bulk shear could set off isolated convection which would likely be in the form of supercells with hail. Will be watching I-35 tomorrow as well. Stay tuned!

Severe Weather to Threaten the Plains Again

2011-04-06T10:01:00.001-05:00

What a rocky few days to say the least as Sunday threw Tuesday a record setting severe weather event took place as overall 1,759 reports of severe storms struck the area including a record setting number of reports on Monday as 1,377 reports for a 1 day total. Surface high pressure is well to the east of the area in Georgia with low pressure setting up in southwest Kansas so that pressure gradient is creating windy conditions with wind gusts between 25 to 35 mph becoming common- there is a threat for wildfires in parts of the area as a combination of strong winds, humidity values below 30 percent and a dry soil are in place across the area and red flag warnings are up east of Oklahoma City and fire weather watches placed west of Watonga and it would it would be a good idea to stay indoors. Along with the gusty winds this is also setting up return flow as mid 60 dew points are forecasted to return to the area but tomorrow night there is a threat for isolated strong storms mainly in the northeastern part of Oklahoma however there is a capping inversion in place so any storms that fire tomorrow will be very isolated but if one does develop the combination of moderate instability , 0-3 helicity values of 250-300, and significant wind shear will allow it to become super cellular with large hail and damaging winds although a tornado would be possible as there is turning of winds with height. That's what leads us to the severe weather threat Friday threw Sunday. A very potent trough with an associated closed low will dig threw the region. A strong cap will be in place however from the morning hours till early afternoon hours. Surface temperatures expected to soar into the upper 80s to 90s with surface dew points in the upper 60s to 70s allows strong amounts of instability to develop with cape values reaching 2500-3000 j/kg. By that time showers and thunderstorms should be developing across the region with large hail and damaging winds with tornadoes also possible as there is twisting of winds with height but helicity values are not that much and that's what leads us to the day 3 outlook by the spc boys.

By Saturday the trough should be really digging in as the strong wind fields just absolutely crank out I'm talking winds of 90 -100 mph at 500 MB or 18 thousand feet also helicity values will be increasing as well however a decently capped airmass will be in place. However as the night progresses showers and thunderstorms should start to develop and eventually congeal into a severe squall line with wind large hail, damaging winds and a few tornadoes. Since the wind fields are expected to be stronger the the previous severe weather event the threat for significant wind damage will be much higher with a derecho possible. This will continue into Sunday. Once again large hail, damaging winds and isolated tornadoes will be possible. Stay tuned as there is a chance that Zack will be chasing this. On a seperate note Zack will be posting his pictures and video of the chase in Kansas Sunday night as soon as the editing is done your in for a treat!!

Severe Weather To Strike the Plains

2011-04-03T13:36:00.000-05:00

What a windy day it has been so far and that's pumping in warm, moist and unstable air into the region you may have noticed that when you walked out this morning but there's a small problem with that in the form of isolated to scattered severe thunderstorms later tonight.Looking at morning model runs things are defiantly shaping up to be an active day in the plains with a moderate risk of severe weather issued. One thing that bothers me is the fact that the spc has eliminated the slight risk over central Oklahoma and I think that's a big mistake. Yes there WAS a fairly stout capping inversion east of the dry line however latest mesoanalyis shows cap weakening to -350 where earlier it was quite stronger and that has allowed ML capes to rise to 2000- 2500 j/kg with SB capes already at 3000 j/kg. Throughout the rest of the day confidence is increasing that initiation should occur between 6 and 7 tonight and that is shown quite well by the HRRR model.

I know it doesn't look as impressive as the qlcs in Missouri but as always models have tendency to under do things and giving the high amounts of instability and shear present once the cap is breached storms should rapidly become severe with very large hail probably as large as baseballs givin extremely high mid level lapse rates of 8-9. Wind damage and isolated tornadoes will also be probable with the storms that develop. While this will not be a tornado outbreak for Oklahoma and Kansas any super cell that can take advantage of strongly sheared and high instability environment will have the potential to put down a large tornado. Zack and Brady are heading right into that area where 0-3 km EHI values are between 10-13 by 0z tonight. Eventually storms will form into a qlcs and move east across the rest of the region producing large hail ,damaging winds and a tornado threat with it during the overnight hours now this is where things can get tricky. During the overnight hours the qlcs will tend to weaken at least thats what the models are thinking and then during the late morning hours as heating takes place they will re-intensify however east of the qlcs theres a cap in place but a breachable cap and there is a potential for isolated supecell thunderstorms develop ahead of the line and once again there will strong shear and instability so one or two large tornadoes are possible and then if that isn't enough another severe weather threat later in the week more on that later. Keep safe y'all.

Cap Could Thwart Storm Initiation Sunday...

2011-04-02T20:28:00.006-05:00

A brief look at Sunday's parameters and you'd be screaming tornado outbreak, however another look at the menacing mixed layer capping inversion is a complete turnoff to the average chaser. I won't lie, temperatures as warm as they are in the 700-850mb layer is not exactly enticing to tomorrows setup but regardless OSN will be leaving bright and early for a target just north of the Oklahoma/Kansas border around the Arkansas City and Wichita Kansas vicinity.

I personally believe that there is a good chance that the cap can be overcome and the most likely areas to see storm initiation tomorrow will be near a triple point across south central Kansas. A triple point for those who do not know is the intersection of differential air masses usually the dry and hot air from the southwest(dryline), maritime air mass from the south and east(warm front), and cooler and drier air to the north(cold front). A triple point is almost always characterized by strong low level convergence and this will be the most likely area where an updraft can overcome the cap and mature into a supercell. Otherwise the dryline extending along or just west of I-35 tomorrow is a gamble for sure.

I anticipate an isolated supercell or two to develop in this area tomorrow and if one can sustain itself there is a high likelihood that it will become very intense capable of producing very large hail, damaging winds, and isolated tornadoes. Below are a couple of select 12z NAM graphics that have grabbed my attention for tomorrow

The GFS and NAM are in fairly good agreement on where to place important surface features tomorrow though the NAM has been back and forth in placing the dryline along I-35 or just west while the GFS has been consistent in keeping the dryline near US highway 81 west of I-35. By 00z-03z dew points well into the 60's will have advected north well into the central plains with moderate-extreme instability in place. For the first time this spring in the plains we will not have to worry about whether or not the thermodynamic profiles will be fully realized across the warm sector as strong low level return flow has been in the process today pumping rich Gulf moisture into the southern plains under idealized trajectories with surface ridge in favorable position. A significant shortwave trough(actually part of a developing longwave pattern) will eject towards the central plains spreading a fairly decent jet streak over the plains by tomorrow evening with low level jet cranking towards sunset. Large looping hodographs per forecast soundings are suggestive of supercells with attendant tornado potential if one is able to take full advantage of shear environment. The parameters discussed above are the reasons why I'll be out and about tomorrow regardless of the strong cap because if something does go up we will potentially be in for an interesting evening. If the cap does hold its ground at least I will have made sure I had not missed out on anything. Stay tuned to our facebook page and this blog tomorrow afternoon and evening for updates throughout our chase!

First Significant Tornado Outbreak(s) Of The Season?

2011-03-31T22:28:00.002-05:00

Sunday and Monday are being eyed as possibly the first two significant tornado outbreaks of the spring season with Sunday(day 4) starting in the plains and shifting to the Mississippi river valley by Monday(day 5).

For the first time this season the high resolution NAM and GFS models are depicting optimal moisture return across the extent of the warm sector with near 70F dews ahead of a sharply defined dryline portrayed to be along or just west of I-35 Sunday evening. By late afternoon and early evening a significant shortwave trough will be ejecting into the central/southern plains spreading a 50-70knot jet streak over the warm sector characterized by moderate-extreme instability(the latest GFS and NAM runs have had MLCAPE values exceeding 4000jk/g). The last two runs of the NAM have the low level jet hinged to the dryline with backed low level surface winds leading to enlarged hodographs and large 0-1km EHI values in excess of 6-8. This suggests a favorable environment for supercells if a mixed layer cap can be overcome. The NAM weakens the cap and breaks out precipitation by 00z Monday which has likely put many chasers over the edge including myself. OSN is definitely keeping an eye on Sunday and we will likely be out and about if things come together. This could be a significant weather event if the shear lines up just right.

By Monday the risk for significant severe weather shifts into the Mississippi river valley where low level shear will further increase across a broad and uncapped warm sector. A tornado outbreak would be most likely on Monday in this region. Make sure you keep checking back regarding our chase status for this weekend and continuous updates on what could be the first major plains chase of the year!

Getting Back On Track...

2011-03-28T22:01:00.002-05:00

The website and this blog I admit have been rather dead lately. We redesigned the website a couple of weeks ago and you would expect that we would be on top of things but shamefully we haven't and I apologize. I'm nearing the end of my Senior year and between school and parents going through a divorce it's been pretty rough for me and I have been less than motivated to do much with this blog. Donny has been in California since February and is due back this Friday and with his return you can expect that the website will be coming alive again if you will.

At least for my sake the weather has been pretty tame this month which considering it's spring time in Oklahoma is pretty odd but not entirely unusual. When you are coming out of a moderate-strong La Nina and have a currently negative NAO/positive PNA there isn't much going for severe weather season in the plains. Now if you live in the southeast that's a different story and this weekend offered no respite from the constant battering from severe weather. The battle so far this spring has certainly been confined to the southeast thus far. This week doesn't look very eventful either other than the chance of rain we have tonight/tomorrow with passing shortwave. Trough will begin amplifying over the east while ridging develops out west putting the plains in a northwest flow suppressing optimal gulf moisture south and east of here and keeping us on the cool/dry side of things. By the weekend ridging translates east and a considerable warm up will ensue for the southern plains with high temperatures rising from below to above normal. From one extreme to the other.

Again though I'm not complaining too much about the quiet weather as if it were active it's not like I would be able to chase anyways. Money is pretty tight at the moment and I also have no means of transportation for now. There are signs though that by mid-late April the pattern will begin shifting to one more favorable for western troughs which in turn increases the severe weather potential for the plains. Time will tell.

I appreciate everyone's understanding and patience with me as I go through one of the great trials of life. I can assure you though that next month will bring about more blogging and more weather to contend with hopefully. Thanks for reading.

Watching Dryline For Thunderstorm Development

2011-03-22T17:43:00.003-05:00

A dryline has divided the state with different weather being experienced on both sides. Behind the boundary the flag has been raised for wildfires with very low humidity, temperatures well into the 80's, and westerly winds gusting to 50mph at times due to the deeply mixed boundary layer. There have been a few large wildfires evident on both visible satellite and radar reflectivity across parts of western and northwestern Oklahoma.

Meanwhile on the other side we are monitoring a conditional risk of severe weather. Deep layer shear and modest low level moisture ahead of the dryline would favor severe thunderstorms however this air mass was capped by an elevated mixed layer and while a few showers have been noted on radar(see above), they have not been able to sustain themselves. If a thunderstorm can develop and sustain itself severe weather is very possible if not likely with large hail and damaging winds being a concern. I'll be honest, I'm not too excited for much if any development along the dryline here in Oklahoma as capping appears too strong and will further increase after sunset. Farther north across the north central plains and parts of the midwest, an outbreak of severe thunderstorms is in progress with numerous severe and tornado warnings out as I type this. This is also where the greatest upper level support exists to overcome the cap and where a tornado watch is currently in effect.

I don't see a whole lot in the way of rain or cooler weather through the remainder of the week. Some of the computer models show some interest in rain/thunderstorm chances towards the end of the weekend into early next week. We really do need the rain.

I may or may not be switching over to wordpress in the coming days or weeks. I haven't been very motivated by the current blog lately and I just feel the need to refresh and start anew. I also like to try new things. We'll see what's to come of this blog in the future and I'll be sure to let my valued viewers know when or if the switchover takes place.

Conditional Tornado Threat This Evening!

2011-03-19T15:24:00.003-05:00

The severe weather threat across Oklahoma is increasing this afternoon and into the evening hours. Surface analysis shows warm front lifting gradually north from southwest into central and eastern Oklahoma with temperature gradient leading to the development of surface low pressure from just northeast of Oklahoma city and southwest of Tulsa. This area of enhanced convergence has led to the development of a linear band of thunderstorms along I-44 in the vicinity of surface low. Other elevated strong-severe thunderstorms were occuring in warm air advection regime across north central Oklahoma where there have been reports of hail as large as golf balls at times.

My concern is the warm front where influx of deeper low level moisture is overspreading central Oklahoma and increasing MLCAPES(currently aoa 1500jk/g) have been noted. Developing backed surface winds are increasing convergence along the warm front and removing mixed layer above the surface which should increase the potential for additional thunderstorm developing from central into southwestern Oklahoma later this afternoon and evening. Thunderstorms rooted to the warm front will likely take advantage of bulk 0-6km shear and strengthening low level jet towards evening possibly taking on supercell characteristics with the threat of very large hail and even an isolated tornado or two. This activity will be strongly rooted to the warm front as storms moving farther north into less favorable thermodynamic profiles will likely become elvated in nature with more of a hail threat.

A severe thunderstorm watch is currently in effect for northern Oklahoma(mainly north of I-40) until 4pm but a replacement watch is likely per the latest mesoscale discussion issued by the SPC and this one could include central and parts of southwestern Oklahoma. Unfortunately we are not chasing this afternoon/evening due to family plans. However tomorrow could feature a similar setup farther north and west and we are considering a chase tomorrow. Stay tuned!

The New OSN! ; Active Weather Pattern Next Week...

2011-03-18T00:22:00.004-05:00

It's been a long week behind the scenes with us working hard on the new website which has now been officially launched. http://www.oklahomaskies.net has been redesigned and I am pleased with the turnout. There are still a few bugs that need to be worked out and we are still working on adding content, but the website is now back up and running to its full potential and all links and pages should be working. A few things to point out:

Tabbed Navigation. One of the most notable changes has been to the navigation bar which are now "tabs" embedded in the header of the website. Whenever one of the links are hovered over or clicked on they display as a tab.

Sidebar Displayed On The Left Side. We did a lot of rearranging to the content, adding some new things and removing others. The sidebar is now displayed to the left with the latest news from this blog and current weather conditions. There are some other things being worked on that will be added in the future.

Chase Status. One of the new features added to the website is our "chase status". You now have the ability to find out what day(s) we are watching for a potential chase! The chase status is integrated with the SPC convective outlook format with "days 1-3" and "days" 4-8". If we are not chasing it will display "No chases anticipated". If we are watching/planning a chase there will be three levels - Low, moderate, and high. The levels are pretty self explanatory. If there is a chase day you can click it and the SPC outlook for that day will come up.

Browser Compatibility. There are some notable difference when cross browsing our website. In firefox, the tabs will be rounded as will the edges of the main content area. This is the intended look for the website. However in Internet Explorer rounding is not displayed with the tabs being squared as is the content area. This is because IE is not a modern browser and some of the CSS code does not work on it. So if you are wanting the best VIEWING experience then Firefox or Google Chrome is recommended. Otherwise it's not a big deal as everything works just fine in Internet Explorer it will just look different in some areas.

We hope you guys like the new look and if you have any suggestions for improvement or something you might want to see added please let us know.

Meanwhile we had downright hot weather conditions out there yesterday with highs in the 80's and 90's across much of the state. The windy and dry conditions did not help the fire situation much but red flag criteria never materialized due to the somewhat higher RHs closer and especially east of I-35 though western Oklahoma did flirt with the red flag criteria for awhile this afternoon as a dry line punched into that part of the state.

The dry line will be a big weather player this weekend into early next week as will a cold front/eventually warm front. We were initially liking the possibilities of a chase worthy setup on Sunday but it is looking less likely that quality shear/moisture will be in place as the trough will remain hung up across the western states until Monday and bountiful low level moisture suppressed by developing cyclogenesis over the southern high plains this weekend. Although there will likely be a few high based showers and thunderstorms near the boundaries Saturday and Sunday but anything more than marginally severe hail/wind would surprise me.

By Monday-Tuesday said trough ejects into central plains spreading belt of 70-80knot westerlies over the southern plains and spreading height falls over dry line/frontal boundary. Thunderstorm organization will increase and the risk of severe weather will also increase. The SPC has Monday highlighted across parts of the southern high plains but we will likely not be chasing due to school/work. It's a shame that the weekend couldn't pan out. We desperately need some moisture so I'm hoping early next week does bring about some rain and thunderstorms!

Wildfire Outbreak Leaves Oklahoma Burning...

2011-03-11T20:18:00.008-06:00

Fueled by the very dry, warm, and windy conditions numerous wildfires broke out and quickly became out of control. A significant wildfire in Oklahoma county earlier this afternoon burned 39 homes in Harrah and Choctaw including the Harrah high school, and prompted mandatory evacuations. A similar event occurred within the past couple weeks in the Texas panhandle when 30,000 acres were burned northeast of Amarillo.

The images show the numerous fires covering Oklahoma this afternoon and the red flag warnings for much of the southern plains.

The late winter and early spring months are typically considered Oklahoma's wildfire season as it is our driest time of the year. However this year the wildfire season has been magnified by the utter lack of precipitation this winter and developing/worsening drought. Today's outbreak could be a precursor to a bad fire season for the southern plains unless appreciable precipitation can be met in the coming weeks/months. Looking at the medium and long range models it does not appear that any substantial precipitation events are in our future and warm and windy days like today can easily amount to a dangerous situation. Tomorrow should feature higher humidity and somewhat cooler temperatures behind a cold front tonight so the fire situation should improve a little.

As a little side note, we are working on a website transformation for OSN that will be taking place during the course of next week. We are excited to bring about new things to the website and make room for future improvements, so be on the lookout for the new OSN!

The Spring Roller Coaster Ride...

2011-03-08T21:38:00.004-06:00

Yes I know, there's been a long delay in blogging lately. I could go into the details as to why there hasn't been a lot of blogging due to school/homework to being busy to lack of weather, but I'll spare you the excuses. Just know that we're still alive and still here. lol.

There really hasn't been a lack of weather lately. In fact there have been day to day fluctuations in our weather at times and this is nothing unexpected. March is typically what meteorologists refer to as the "transition month" where we transition from winter to spring. March can feature/has featured a volatile weather pattern with big temperature swings and wild weather systems. This is because the temperature gradient begins to strengthen as we head towards spring with cold air trying to maintain its ground while the tropical maritime air begins to surge north. The frequent "clash" of the two air masses often leads to our severe weather season and today was just another example of this "clash".

Today was a dreary, raw, and chilly day for Oklahoma as continental and pacific cold fronts quickly ushered in drier and colder air masses from the north and west. There was some precipitation early in the day with afternoon thunderstorms developing near the dry line along and south of the red river across northeast Texas and these storms are ongoing as I type this though a steady weakening trend has been observed. A tornado watch was in effect earlier this afternoon for the aforementioned area with one supercell producing several tornadoes in Lamar and Red River counties in Texas. Just a typical spring day in tornado alley. ;)

A progressive weather pattern will be maintained this week with northwest flow continuing through Thursday across the southern plains as trough amplifies across the east. By Friday temperatures will have rebounded into the 70's with return flow bringing gulf air mass back into the southern plains in time for the next shortwave late this weekend. I don't think severe weather is much of a concern with primarily low amplitude, however showers and thunderstorms would appear likely along cold front Sunday night into Monday. To me this isn't really an exciting weather pattern with not much in the way of IMPRESSIVE troughing across the west. This is mostly due to a now positive PNA. There are some signs that blocking could return across the north Atlantic(negative NAO) which would in turn recreate the same weather pattern we have become accustomed to over the winter. Let's hope not. I need a good plains chase already!

Pictures From Sunday's Storm Chase!

2011-02-28T20:38:00.007-06:00

An isolated supercell developed near the triple point late yesterday afternoon and evening as anticipated and produced significant severe weather across parts of northern Oklahoma and into southern Kansas near the KS/OK border. We followed the storm from the Medford/Deer Creek area in far northern Oklahoma to Coffeyville KS just north of the KS/OK border.

This was looking to the north and west towards Medford, OK as the storm was beginning to take on supercell characteristics with a mesocyclone visible at the base with developing rotation. The storm was severe at the time with reports of golf ball sized hail in the area. Notice the rock hard updraft tower taking full advantage of the thermodynamic environment. The cap had obviously lost.

We were near Deer Creek, OK at the time of this picture and what is cool is you can see the "hook" portion of the supercell. Clear slot is also visible and rotation is evident. The dark blue color towards the bottom left is the precipitation core where heavy rain and hail was likely falling.

Condensation funnel develops shortly thereafter and at this point the storm was tornado warned. We quickly lost contrast of the developing tornado as we made a bad road decision deterring from I-35(when we should've stayed on I-35 heading north). The storm was moving quickly to the northeast.

We are now loosing daylight and I'm beginning to get frustrated by my poor decision. When storm chasing there is quick decision making to be done and one bad call can cost the whole chase... luckily for us we were given a second chance, albeit it was dark. I then decide to take 77 north towards Arkansas City, KS(at the time the storm was crossing the border after producing the tornadoes near Grainola, OK and Newkirk, OK). When we get to Kansas, its dark... the chances of a photogenic tornado are gone. However I was not about to give up. We turned at the intersection on US highway 166 and raced east. There was another chase vehicle ahead of us and I knew I made a good decision. The storm was still tornado warned, a textbook cycling supercell taking full advantage of the warm sector with no competition from other storms. This storm was very electrical too, amidst the flashes of lightning we saw a large wall cloud and tornado extending to the ground just southeast of Sedan, KS. We bagged one. Unfortunately however, I do not have a picture of our catch as it was dark and I had only 13 seconds of video on my camera because I left my memory card at home(I know... smart one...). After following it for awhile longer towards Coffeyville, KS I decided it was getting late and we got off the highway and headed back south towards I-44 and then home abandoning the storm.

It was a great chase and a successful one compared to our chases last year where we were literally unprepared most of the time. For February this was a very impressive supercell and hopefully a sign of things to come! Most of the activity from yesterday stayed near the warm front where CAP was weakest. Moderate risk never panned out across Arkansas and southeast Missouri where the CAP held. View our complete set of pictures here![coming soon...]

Targeting Triple Point This Afternoon/Evening!

2011-02-27T09:59:00.003-06:00

After careful consideration, we have decided we will be chasing this afternoon/evening targeting the triple point across north central Oklahoma. This looks to be our best bet for seeing diurnal activity.

The RUC and other high resolution models are hinging on the idea of a stronger surface low across the southern high plains with dry line bulging into central/north central Oklahoma by late day. Warm front will begin retreating south as cold front by late day and will setup near the KS/OK border by late afternoon and early evening. The point of intersection of the dry line, surface low, and front is described as the triple point and the most likely location to see daytime convection today as the main show will occur farther east across the Ozark Plateau during the night where there is currently a moderate risk.

Lower severe probabilities are included farther to the west to account for dry line near I-35 and triple point located across north central Oklahoma. It is important to realize when making decisions that SPC convective outlooks are based on COVERAGE and not necessarily how severe a storm will be. With that being said anything that goes up farther west will likely be just as severe but the odds of convection initiating this far west is quite low due to a mixed layer cap(MLCINH) which is forecast to be quite strong for much of the day. After reviewing some of the convective models this morning I believe there is a good chance that something isolated may form near the triple point. This is much closer to the baroclinc zone(or area of frontal lift) and where forcing/convergence will be stronger. This leads to higher odds of the cap being breached. If storms do develop the atmospheric environment looks primed for supercells(at least initially) with large hail and an attendant tornado threat. 0-1km EHIs displayed above(right) are absolutely impressive for this early in the season. Low level jet(displayed left) will intensify this evening with RUC showing backed surface winds. This leads to enlarged and curved hodographs which indicate turning with height and the potential for rotating supercells.

Preliminary target is in the vicinity of the Enid area. The bad thing about these early season setups are the fast storm motions with strong jet streak above the surface. Storms if they develop would likely move in excess of 50mph! Wish us luck!

Significant Severe Weather Outbreak Tomorrow!

2011-02-26T11:47:00.003-06:00

A moderate risk(second of the year) has been issued for parts of eastern Oklahoma and into the Mississippi river valley in anticipation of yet another outbreak of severe storms. The difference between tomorrow's setup and last Thursday's is that more instability will be present across the warm sector complimenting strongly sheared environment.

A significant shortwave bringing rare low elevation snow to parts of southern California(!) will translate east tomorrow becoming a positive-negative tilt trough across the plains and spreading a 80-100knot+ jet streak across warm sector by late Sunday afternoon and evening. Rich boundary layer moisture will be in place to the east of dry line which will set up somewhere near or just east of US highway 81 with increasing MLCAPE(instability) by evening as surface temperatures cool in contrast of rather warm mid level temperatures. With more instability present this time around, confidence in a significant outbreak of severe weather is higher(hence the moderate risk issuance). Thursday's moderate risk I believe was jumping the gun as a substantial tornado threat never did materialize due to lack of sufficient destabilization(although there were several tornado reports).

If I were chasing tomorrow I'd play the dry line in Oklahoma or near the dry line/surface low intersection near the OK/KS border. This would be the best opportunity at seeing daytime activity. The only problem with areas farther west is the "CAP" which will be relatively strong owing to very warm mid level temperatures brought upon by strong southwesterly flow. This will preclude thunderstorm initiation for much of the day until perhaps late afternoon/evening as instability and convergence increases. If storms can get going, the potential for very large hail, damaging winds, and even tornadoes will be quite high. Storm motions will also be very fast to the ENE between 50-60mph! Not an ideal chase if you ask me.

Confidence in storm initiation is higher farther east(another reason why the moderate risk was issued) as forcing along the dry line/approaching cold front increases. This will also mean probably a quick transition to linear mode or squall line. Tornadoes will still be very much possible if not likely in any embedded supercell structures and/or discrete development. The event across the moderate risk will be nocturnal which makes this a potentially dangerous situation across the moderate risk.

To the west of the warm sector behind the dry line, very strong westerly winds gusting to and over 55-60mph are likely with high wind watch issuance across the Texas/Oklahoma panhandles. Fire danger in this area will be extreme and of equal concern. The models have been trending to a slower dry line advancement into Oklahoma which may limit the wild fire potential to far western Oklahoma(which would be a good thing), but surface trends will need to be watched carefully tomorrow. Like I mentioned above, I'm probably not chasing tomorrow given high uncertainty in diurnal initiation and fast storm motions. I'll keep an eye on things however.

Conditional But Potent Severe Threat Sunday!

2011-02-25T21:10:00.007-06:00

Thursday's severe weather served as Mother Nature's heads up that spring/storm season is just around the corner and following on its heels comes another significant shortwave trough arriving in the southern/central plains Sunday.

The aforementioned system is currently bringing heavy rains and mountain snows to parts of California first however. Similar to the previous storm, this system is sliding down the California coastline but much closer too unlike the first one. This allows for colder upper levels to develop with the interaction with land and therefore intensifying the system. As we head into Saturday the trough will become positive tilted before beginning to take on a negative tilt as it arrives in the plains Sunday.

The models are fairly impressive in showing a 80-100knot+ jet streak overspreading the southern plains by Sunday afternoon/evening. Warm front will return northward tomorrow bringing back richer low level gulf moisture leading to the development of a warm sector to the east of a sharpening dry line(which will be located in the vicinity of I-35) Sunday afternoon. What's also interesting is models show more instability present with a greater temperature contrast. This will also lead to the development of cyclogenesis across the southern high plains by evening. Backed low level flow, favorably sheared warm sector, and the presence of moderate instability near dry line will yield to the development of severe weather with storms that can get going. My concern is a strong capping inversion that will be present as strong southwest flow brings warm mid level temperatures. For those who don't know, the CAP(also known as CINH or convective inhibition) is the name for the warm mid level temperatures that act to put a lid on or "cap" the potential convective energy and therefore hindering the development of thunderstorms. NAM model suggests storms will not fire until well after dark and this will not be in the favor of the storm chaser. Regardless if a storm can get going, the parameters will be favorable for all modes of severe weather.

To the west of the dry line we must not forget about the fire danger which will be enhanced greatly by insane westerly winds which may gust to 60mph out in the Texas/Oklahoma panhandles(non thunderstorm related!). A High Wind Watch is in effect. Fires will easily be out of control if they develop. Western/west central Oklahoma are also included in a fire weather watch where extreme fire danger may develop in these areas as well.

Right now areas across eastern Oklahoma, southeast Kansas, and into the mid Mississippi river valley are included in a slight risk for severe weather per the day three SPC outlook. I suspect this may be shifted farther west towards or just west of I-35 as a conditional but potent severe weather threat exists near the dry line albeit capped. OSN chase operations for Sunday will revolve around whether or not the CAP can be overcome and the plans of chase partner. There will be a new post tomorrow.

Severe Weather Outbreak To Target MS River Valley Thurs!

2011-02-22T20:48:00.004-06:00

Computer models show a favorably sheared warm sector with 60F+ dew points advecting north ahead of strong Arctic cold front and sharpening dry line, setting the stage for an early season severe weather outbreak from the Arklatex region into the lower Mississippi river valley Thursday afternoon and evening.

The graphic to the right shows the setup early Thursday morning with strong to severe convection likely firing early in the morning near I-35 as large scale ascent increases with developing surface low and a strengthening 70-80knot low level jet. The main threats with early morning convection will be large hail and strong winds.

As surface low deepens and shifts northeast during the afternoon, strong low level and deep layer shear in excess of 50-60knots will develop on the southeast quadrant of surface low with warm/moist air mass ahead of cold front/dry line in Arkansas. Ongoing convection will likely strengthening with eastern extent and supercell thunderstorms and line segments will be possible capable of all modes of severe weather. This looks like a high shear low cape event which are quite frequent across the Mid South late winter/early spring. February 5, 2008 was a prime example. Residents in the aforementioned areas are encouraged to stay weather aware this week, especially with the height of the event likely occurring around/after dark. Behind the cold front comes abruptly colder/drier air for the southern plains ending any severe weather threat and ushering in winter. Another more potent storm system will arrive late this weekend with the possibility of heavy rain and perhaps severe weather. More on this system later.

There will be no chase operations for OSN Thursday as the action will be primarily east of Oklahoma.

All Eyes On Thursday

2011-02-20T17:04:00.003-06:00

It's Spring! Almost... It's amazing how dramatic the weather has changed in one whole week going from snowpocalypse to spring fever. The temperature turnaround last week was nothing short of phenomenal with some locations warming a whole 110 degrees!

So why the turnaround? It was inevitable that La Nina would take hold sometime this winter, but as I alluded to beforehand the development of high latitude blocking would offset the ENSO event and this was the case. Now that the blocking has been removed, the pattern has become progressive and the eastern trough has been replaced with a ridge and the complete opposite across the west. A negative PNA/positive AO/NAO tends to do that. However this type of pattern can also evolve into an active one in terms of severe weather and Thursday could be an example of that.

I have to be honest seeing this this morning had me trigger happy. If this forecast pans out you can count on me being out on a storm chase Thursday afternoon and evening. 18z GFS model to the left shows shortwave ejecting into the central and southern plains with a 70-80knot jet overspreading a developing warm sector ahead of Arctic cold front and dry line(not pictured). The perpendicular flow aloft to the dry line cold front would favor more discrete thunderstorm development(supercells) rather than linear(squall line). Nice theta-e advection bringing relatively deep low level moisture northward ahead of sharpening dry line would certainly favor surface based convection and this could be a fairly significant early season severe weather outbreak. The SPC has shifted into high gear issuing a day 5 outlook(pictured right) highlighting parts of the southern plains and much of the lower Mississippi river valley as an area of interest. For Oklahoma the best risk of significant severe weather will be near and east of I-35 the way it looks at the moment but this outlook is liable to change several times this week leading up to the event. In fact some of the later runs have trended somewhat farther west though the best low level shear still appears to be across Arkansas. This is definitely something we will be watching this week. How convenient that it occurs during severe weather awareness week for the southern plains!

Progressive pattern brings in another system by weekend/early next week with another following thereafter. It's all part of an active weather pattern that's ahead! And yes unfortunately the aforementioned Arctic cold front will be bringing some much colder air into the area by next weekend... don't shoot me!

Gary England Says Not To Worry But He Speaks For Himself!

2011-02-18T22:44:00.008-06:00

Gary England tonight on live television made it clear that he's not on our side. Don't get me wrong I used to admire him as a meteorologist and he saved countless lives during the May 3rd 1999 tornado outbreak. He was my inspiration in my younger years. Nowadays not so much. I have had no real beef with Gary however until tonight.

In the video above Gary states that the budget cuts proposed by congress may not be such a bad thing. He said we shouldn't worry... well it depends on who you are talking to. Maybe for those who rely only on television weathermen and/or yourself then there probably ISN'T anything to worry about. This is because this isn't coming out of your pocket right? Most private media companies such as KWTV, KOCO, KFOR, and the likes have their own forecasting tools and are funded elsewhere. They don't rely completely on the NWS so no they shouldn't be worried.

However those like myself who are working towards a career at the National Weather Service, us storm chasers who rely A LOT on their resources, we have every right to be concerned and we should be. Now I agree the spokesperson for the NWS on the above video was a bit extreme but he makes a valid point. These budget cuts will do more harm than good. I agree that cuts need to be made but the NWS is not the place to do it. If this bill passes we are cutting one of our most vital resources. I don't like to hype things more then they should be but this bill means a lot to me as it most definitely holds the key to my future now. If they have to furlough and reduce the staff the chances of me getting a job at the NWS down the road are reduced greatly. If there is a lack of funding for the forecasting tools that are heavily used to predict the weather how are we supposed to do our job and correctly?

I'm sorry Gary but you need to think before you speak. Just because you have nothing to worry about doesn't mean there aren't others out there that do.

Protect our NWS! Visit this link for more information.

From One Extreme To Another...

2011-02-18T18:19:00.005-06:00

An incredible 110 degree temperature swing was accomplished at Bartlesville, OK which recorded a high of 82F yesterday afternoon. Just one week prior the morning air temperature was -27F! The 110 difference is likely one of the greatest temperature swings in U.S. history!! Record highs were also set at Will Rogers World air port which reached 80F yesterday afternoon.

The wild temperature swing was brought upon by a "chinook" wind which is a westerly wind component and is also referred to as a downslope wind. What happens is wind running down the Rocky mountains(downslope) sinks and warms considerably. Chinook winds are known for their resulting dramatic warm ups across the plains and some people consider them "snow eating" winds as well as the warm wind rapidly erodes snow cover(as we also saw). The above average temperatures continued this afternoon and will persist through the weekend before a continental Polar front brings colder air into the southern plains by Monday. There will likely be dense fog tomorrow morning along the northern periphery of returning humid air mass from the south and east... much similar to what was experienced Wednesday morning. Just a heads up.

House Budget Proposal Will Have Detrimental Effects On Our Forecasting Ability If Passed!! I'm not big on politics, but a continuing resolution proposed by the House if enacted will cut the NWS's budget by 30%. This will likely lead to the furlough and rolling closures of NWS offices around the country and prove to have a disastrous impact on forecasting ability! The reduced funding will basically flush years worth of advancements in forecasting technology down the toilet. Forecasts will become unreliable as data may be up to 36 hours old due to the likely shutdown of major forecasting tools because of lack of funding! Read the full article here.

This is very unsettling to me as it would affect my future career as a meteorologist and also elevate the risk of loss of lives and property due to lack of information so it's something that will effect everyone and not just us in the weather department. You can find out information on how you can help out by visiting this link. In my opinion the NWS is NOT the place to deduct funding and will prove to be a very imprudent decision if made.

Western Troughs Return!

2011-02-15T20:57:00.005-06:00

The better part of the winter has been characterized by high latitude blocking producing a persistent east coast trough and west coast ridge with northwest flow across the plains(much like last winter). This type of pattern is notorious for persistent cold with uninterrupted flow out of north and west Canada/Alaska. Finally downstream blocking has been erased which is confirmed by the now positive NAO and AO. The PNA has become negative which correlates with west coast troughing and this has been the case recently.

The pattern has "flipped" if you will with a trough now in the west and developing height rises across the plains and points east alluding to a developing ridge. Southwesterly winds(also referred to as downslope or "Chinook" winds) have allowed for an impressive warm up across the plains with high temperatures climbing above normal for a change. Warm weather and breezy south and west winds will be the rule for the remainder of the week for Oklahoma. We will likely see the large area of negative anomalies centered across much of the central and southern plains trend positive with the stretch of above normal temperatures. As they say here in Oklahoma "if you don't like the weather give it 5 minutes and it will change!"(in this case a week's span).Check out the 500mb chart from today's 12z ECMWF depicted Sunday morning(2/20/11). Large closed low across the west coast transitions to a progressive open wave as it is ejected into the central and southern plains. The GFS shows this scenario as well. Quickly on its heels comes another trough mid-late next week followed by another system... and another! This is the kind of pattern that us storm chasers like to see as usually it evolves into one favorable for severe weather. The trough this weekend could produce some severe weather in parts of the southern high plains Sunday evening into Monday with several days of low level return flow bringing near 60F dew points northward into a favorably sheared warm sector ahead of cold front and dry line. It usually does not take a whole lot to produce in these early season setups so it's certainly intriguing. The trough coming in next Wed/Thurs looks even more potent. Of course limited moisture and instability during the early season can become a real problem despite the dynamics being there. This is especially true given the frequently perturbed GOM this Winter with current SSTs remaining below average for now. We'll see.

We must not forget that Winter is certainly not over. Just because this week has been/will continue to be a much needed break from the cold and snowy pattern to open up the month doesn't mean we're done. In fact some long range indicators suggest that height rises will redevelop across Alaska and the return of the Arctic hounds late this month.

Colder Than The South Pole!?

2011-02-10T19:52:00.008-06:00

Temperatures across the state this morning reached record cold levels. The northern 2/3rds of Oklahoma saw actual air temperatures below zero and in some cases as much as 20-30 below!!

Nowata, Oklahoma set a new record for the coldest Oklahoma temperature since record keeping began. -31F!! To put things in perspective parts of Oklahoma were colder than the south pole(which is the coldest pole on the Earth by the way!!) where the coldest temperature there was -23F.

Even here in Oklahoma City we shattered our old record of 4F set in 1899 and 1929 with -5F by 7am this morning. It is also the first time Oklahoma City has fallen below 0F since 1996 when we hit -3F January 4th.

So why was it so darn cold!? The answer is simple... radiational cooling... but the combination is a complex one that has to come together just right for our temperatures to fall that low.

Consider the very deep snow pack that existed across northeastern Oklahoma. The recent winter storm brought snowfall totals in excess of 20" in some parts of northeast Oklahoma and northwest Arkansas. Even with snow cover heat is still retained but it is reflected back towards space. If there are clouds around it acts to insulate the atmosphere or in other words acts like a mirror deflecting it back to the surface. So we also had to have clear skies. This was also the case. Winds were light if not completely calm and so there was no mixing present. The combination of the fresh snow pack, calm winds, clear skies, and very dry air allowed temperatures to plummet as cold air pooled over the region.

A great example was in Oklahoma City this morning. We were actually at 5F before 7 am with a light northerly wind at around 3-5mph. Typically a north wind is not very favorable for radiational cooling for the metro as it produces the "urban heat island" effect. This is where the concrete and buildings in the city act to trap heat and insulate surrounding areas keeping them warmer than the suburbs or rural areas. At 7am we saw our wind shift to the west and become calm. Out west there is a lot of rural areas and free land. This allowed our temperature to drop dramatically. In fact we dropped 10 degrees in a thirty minute time frame. Just think if we had a calm westerly wind the whole night we could have been some 10-20 degrees below zero like our northern counterparts!

Honorable mentions:
-31F - Nowata, OK
-28F - Pryor, OK
-27F - Blackwell, OK
-27F - Bartlesville, OK
-27F - Medford, OK
-25F - Ponca City, OK
-20F - Stillwater, OK
-13F - Watonga, OK
-11F - Edmond, OK
-10F - Yukon, OK
-5 - OKC, OK
-4 - Norman, OK

This was truly an impressive meteorological event!!!

MAJOR Winter Storm Bearing Down On The S. Plains!

2011-02-08T19:33:00.003-06:00

As Oklahoma finally recovers from the last big hitter, a new storm promises to bury the area yet again with up to a foot of snow.

The current air temperature map from the Oklahoma mesonet shows quite the contrast in temperatures. A powerful Arctic cold front(likely the strongest of the winter season) is bringing bitter cold air into the southern plains. The front can easily be deciphered in the map above with temperatures in the 40's south and east of the front but plunging into the teens and single digits behind it. The temperature at Will Rogers World Airport had fallen to 19 degrees at 7pm CST.

Meanwhile, a potent shortwave was riding a northwesterly flow aloft from the south central Rockies and into the Panhandles of Oklahoma/Texas from the northwest. A large area of snow had developed across Kansas and the Panhandles and was advancing and expanding south into Oklahoma. This trend will continue late this evening and overnight as the storm system moves east and southeast through the area providing plenty of moisture/lift atop a very dry and cold low level Arctic air mass.

I'm calling for 8-12" of snow for Oklahoma City with this system and this will likely shut us down once again. Gusty post frontal winds will also blow and drift the snow which will further complicate travel. Temperatures will plunge to their coldest of the entire winter season with some subzero readings likely across the north and west. Wind chills will be even colder. It's best to just grab a cup of hot chocolate, adjust the heat, and enjoy(or not) the latest beating from old man winter from INDOORS.

p.s. - instead of doing a live blog I will be posting frequent updates on our facebook page for this storm so make sure to "like" us for the very latest!

Blizzard Part II: The Sequel!

2011-02-07T20:34:00.005-06:00

I saw a local news station using this term and thought "what a perfect title for this blog!". It's nearly a repeat of last week's massive storm.

Winter storm warnings have been posted for Oklahoma once again in advance of the storm with winter storm watches covering much of the southern plains and into the lower Mississippi river valley(parts likely to be upgraded to a winter storm warning either tonight or tomorrow)! Current 500 and 700mb analysis shows a well organized shortwave riding a progressive northwesterly flow regime which cuts through the plains(the culprit in our very cold and snowy February so far). Thunder snow(a thunderstorm with snow instead of rain) per observations was being reported earlier this evening around the Salt Lake City area in Utah. Usually thunder snow can be interpreted as a measure of the storm's convective structure and strength and this storm has a lot of it.

The GFS and NAM agree that a large swath of generally 4-6" of snow will fall across much of the southern plains area from the Texas/Oklahoma panhandles into Arkansas. However they differ in the degree of strength and the possible setup of a mesoscale band which will ultimately lead to an area of enhanced snowfall rates and accumulations. The NAM has a much more amplified wave than the GFS and sets up deep frontogenetic lifting over the northern half of the state resulting in a large area of 10-12"+ snow accumulations from I-40 north. The GFS has this feature farther south across the I-40 corridor in central Oklahoma but not quite as much snow(6-8"). I have generally compromised between the two models for now leaving me with a large area of 6-12" snow amounts across much of Oklahoma which seems to be in reasonable agreement with other forecasters as well.

Strong post frontal winds gusting to 30mph+ while not quite as gusty as the previous storm will still be capable of considerable blowing and drifting snow. Low wind chills, subzero at times, are also likely with strong cold air advection and falling temperatures. Travel problems are likely and like I mentioned above(and echoing some of the local meteorologists) it's nearly a repeat of last week's storm just a notch lower. I'll have another update tomorrow.

Thawing Out... However We're Not Done Yet...

2011-02-05T14:40:00.004-06:00

Temperatures this afternoon have risen ABOVE the freezing mark for the first time this month! A Chinook wind(or downslope westerly wind) has allowed for quite the warm up this afternoon across much of the southern plains. In fact, go out west and you'll find 60 degree readings!! Erik, Oklahoma was currently reporting a temperature of 64 degrees! But then again western Oklahoma hasn't received nearly as much snow as areas farther east so we'll take the 45 here in the metro. For the first time since Monday evening I can actually see parts of my street here in Moore. Keep in mind though that temperatures will fall back below freezing tonight and so slush and water will refreeze on the roads.

Then comes our next storm. Satellite imagery and radar composite shows another shortwave sliding southeast towards the panhandles from the south central Rockies this afternoon. Clouds have increased across the southern high plains and Texas/Oklahoma panhandles and will begin expanding into Oklahoma late this afternoon into the evening. A cold front was also approaching the area from the northwest. This isn't an Arctic cold front but there is some modified continental air behind it.

The NAM, RUC, and HRRR break out precipitation across the panhandles tonight and spread it east with the storm system through the overnight. There are some indications that a shallow warm nose present in the 850mb levels will allow precipitation to start out as rain or a mix of rain and snow, though a quick transition to snow is expected as light cold air advection takes over along with evaporative cooling effects. I do not anticipate a lot of snow from this system, similar to Friday's event there will be a band of 1-3" accumulations mainly near and south of I-40. Some of the latest NAM runs have indicated a northward shift in this band of snow and this will be monitored( it is already accounted for in the graphic above). Snow should end west to east tomorrow afternoon and temperatures will be in the low to mid 30's.

Monday will be similar to today with another warm up and flow flattens out. My attention is then shifted to the NEXT system. Given that this system hasn't even formed yet, it is hard to take any particular model run seriously at this point. With that being said both the GFS and ECMWF are alluding to another nasty winter storm for the Tuesday-Wednesday time frame. Both models show bitter Arctic air making another southward plunge down the front range Rockies and into the southern plains with storm system moving east into northwest Texas and amplifying over the area. The ECMWF is the most aggressive model of the two with another 6-12" snowstorm for much of Oklahoma while the GFS suggests 4-8" which still is a respectable amount of snow. After the storm, Arctic high pressure dominates southern plains for remainder of the week before finally a shift in the pattern is observed next weekend leading to increasing temperatures.

Meanwhile check out our video of the January 31-February 1, 2011 Blizzard below! I plan on writing a full summary of the event once this active weather pattern slows down.

The Little Snowstorm that COULD!!!

2011-02-04T07:58:00.002-06:00

Anyone remember the story of the the "The Little Engine that Could"? It kept chugging along with all those trains kept saying I think I can I think I can!! Well this is the little snowstorm that could. Originally this system was thought to have just a tad of moisture and with the cold air in place maybe some snow but this turned out to be more then expected. Heavy snow developed early last night quicker, heavier and more moisture then anticipated in fact it dumped 6 inches of snow in Dallas!!! So what does that mean for us? Numerous winter weather advisories and warnings are out in force today. The winter weather advisories are just shy of Oklahoma City but with cold air in place, a little banding going on snow should rapidly start to accumulate and I expect winter weather advisories to be issued there within the next 1-2 hours. Overall snowfall rates should average 1 inch per hour however with locally higher amounts if you get underneath one of these heavier bands with overall amounts expected to be 1-3'' near I-40 and east of I-35. Zack and I will both be documenting this little snowstorm that could he will be taking pictures and recording while at my house in Arkansas I am time-lapsing the entire event. Rest assured this maybe a prelude of what's to come over the next several days- several snow opportunity's just about every other day followed that could easily double today's snowfall accumulation but it's to early to get into to much details but it could be quite interesting to say the least. As the event draws near for next week we will be making daily updates so stay tuned- and if you have pictures you want to share feel free to email them to us admin@oklahomaskies.net.

LIVE BLOG - Blizzard 2011!(1/31/11 - 2/1/11)

2011-01-31T16:22:00.023-06:00

UPDATE - 10:00PM CST 2/1/11:
The storm has moved out of the viewing area, however roads remain hazardous and travel is not recommended, in fact it's discouraged. Even though the storm has ended blowing/drifting snow will continue overnight with localized ground blizzard conditions.

A WIND CHILL ADVISORY is in effect until noon tomorrow(2/2/11) for all of central Oklahoma. Wind chills of -10 to -20 will be common.

This concludes our live blog. You can visit our homepage for frequent updates on road conditions, closures, etc. Our fb page will also be occasionally updated.

UPDATE - 9:46AM CST 2/1/11:
BOTH NORTHBOUND LANES OF I-35 AT MILEMARKER 53 IN MURRAY COUNTY ARE BLOCKED WITH 6 SEMI TRUCKS THAT ARE STUCK IN THE ROADWAY. SEVERAL TRUCK WRECKERS ARE ENROUTE.

I40 WESTBOUND LANE AT MM212 IN OKFUSKEE COUNTY IS CLOSED DUE TO MULTIPLE VEHICLES BEING STUCK IN 4' SNOWBANK IN CONSTRUCTION ZONE

UPDATE - 9:08AM CST 2/1/11:
WHITE OUT conditions all over the metro. Very heavy snow is currently falling. 2-3" per hour rates. Travel is not advised!

UPDATE- 6:40AM CST 2/1/11:
Snow, heavy at times, will continue to fall across most on central and eastern Oklahoma. Roads are snow packed and travel is highly discouraged. Temperatures this morning are ranging from -2 in the Oklahoma Panhandle up to 41 in the extreme southeast sections of the state. Winds are cranking up with 20-30 mph sustained winds the highest gust I can find is 48 in the Minco area. With the high winds coupled with these low of temperatures it feels just miserable out there with wind chills from -28 in Boise City to 36 above in Broken Bow. This blizzard will continue to wreak havoc over then next several hours. Elsewhere in the south severe weather is starting to break out with the squall line entering western Louisiana. This squall line has a history of producing of damage. On top of this squall line isolated supercell thunderstorms are also forming ahead of the squall line we need to watch these isolated supercells the most for tornadic activity and it wouldn't surprise me to see a tornado watch out in the next 2-3 hours.

UPDATE - 4:18AM CST 2/1/11:Snow, heavy at times, continues to fall across much of Oklahoma. The heaviest snow was falling just to the southeast of I-44 where higher reflectivity bands are setting up. Snowfall rates of 2-3" per hour will be likely in these bands.

For the metro, snow and blowing snow was occurring and will continue through the morning hours. A large and strengthening storm system will continue to produce widespread and at times heavy precipitation over the area. Snowfall totals for the metro are expected to range from 8" on the north and west sides to as much as 12" on the south and east sides. Blowing/drifting of the snow will create very poor visibilities, at times white out conditions and travel is strongly discouraged. Stay tuned for updates.

UPDATE - 11:38PM CST 1/31/11:Powerful winter storm quickly intensifying over the southern plains. Radar showed band of heavy sleet/snow from areas along and south of I-44. Precip will continue to expand in coverage and increase in intensity overnight. Travel is not advised.

UPDATE- 11:00pm CST 1/31/11:
Over the past hour while sleet and freezing rain has been common that transitioning of snow is starting to develop and expand. The band is located along a line from Snyder to Norman to Bartersville. South of that line its still a sloppy mess of freezing rain and sleet. From Moore to just east of Enid to Geary its also freezing rain and sleet- however snow is starting to take over just east of Yukon.

UPDATE- 10:20pm CST 1/31/11:
According to radar snow is starting to take over south of Oklahoma City- along from east of Anadarko to Chickasha to Purcell to Norman and as far south as Rush Springs. From Zack 1 inch of sleet accumulation already. This is why travel is not advised it's coming down hard and quickly accumulating.

UPDATE - 9:52pm CST 1/31/11:
Thunder sleet and snow occurring across the metro right now. From my location I can already report a slushy accumulation of sleet on the pavement.

UPDATE - 9:10pm CST 1/31/11:
Convection is starting to enter parts of central Oklahoma mainly along a line from Mustang to Newcastle to Purcell. Thunder and lightning will be possible in the heaviest cores. The precipitation that is with this convection is not rain it's sleet and freezing rain as temperatures are below freezing- exercise extreme caution if you have to travel although travel is highly discouraged.

UPDATE - 8:19pm CST 1/31/11:
Convection is quickly developing southwest of the metro with reports of freezing rain and sleet.... and so it begins.

and btw, the latest NAM is just outrageous!!

UPDATE - 7:40pm CST 1/31/11:
One model, the HRRR(High Resolution Rapid Refresh), has a large swath of 10+" over much of Oklahoma. Usually the HRRR is a very accurate convective model so we will see how it holds up. Anxiously awaiting the 00z NAM and GFS. We'll update accordingly.

UPDATE - 5:44pm CST 1/31/11:
The freezing line is already approaching I-44 in the metro. Temps will quickly fall below freezing this evening. Meanwhile precipitation is increasing to our south and west and this trend will continue north and east throughout the evening.

We've been talking about the snow itself but I should put emphasis on the wind chills. They are going to be downright brutal. -10 to -20 in some locations. Any amount of time spent outdoors will elevate your risk of developing hypothermia and/or frostbite very quickly.

UPDATE - 4:22pm CST 1/31/11:
A state of emergency has been issued for all 77 counties of Oklahoma in advance of a powerful winter storm that WILL rival the Blizzard we had Christmas Eve 2009.

Blizzard warnings are currently in effect from Oklahoma City and pointing to the northeast. Some Cities in the warning include Norman, Moore, Oklahoma City, Guthrie, Yukon, Stillwater, El Reno, Enid, Perry, Tulsa, Miami. Winter storm warnings are in effect elsewhere.

A powerful storm system will approach the area this evening and interact with a plume of Pacific moisture and modified Gulf moisture leading to the development of widespread and heavy precipitation. Current 18z modeling differed from the 12z as far as accumulations are concerned. The reason for the different perspectives from the NAM and GFS is because the NAM is colder in all layers of the atmosphere while the GFS has a shallow layer of warm air just above the surface. I am going with the colder NAM which means that a large part of the state will receive significant accumulations of snow. Ice accumulations are likely southeast of I-44 say from Ardmore up to Ada and McAlester where .25" of ice accretion is possible.

For the Oklahoma City metro, precipitation may start as freezing rain and sleet but will transition quickly over to snow and heavy snow at that. 8-12" of snow is likely. Totals of 12-20" will be possible northeast of the metro along I-44 in northeast Oklahoma. Will update the snow map later this evening.

The combination of very strong winds(over 40mph), heavy snow, and cold temperatures/wind chills will be a lethal one. It is STRONGLY advised that you stay inside and do NOT venture out in this storm!

We will be updating this blog frequently so check back for continuous updates. Look for our facebook page as well.

Blizzard , Heavy Rain and Severe Weather Oh My!!!!

2011-01-31T08:49:00.011-06:00

Did someone accidentally turn back time to Christmas Eve 2009?? Model runs say no but what's forecasted says yes. Only difference is accumulations should be much higher. Numerous winter storm warnings are in effect from Oklahoma into Western Illinois with winter storm watches are located just east of the winter storm warnings and are located from Indiana all the way threw Boston, Massachusetts. It would not surprise me if most of the winter storm warnings and watches turn into blizzard warnings and ice storm warnings over the next 12-24 hours as conditions will be deteriorating with travel virtually impossible and school closings likely. Right now temperatures are in the low 30s and approach the low 40's with north/northwest winds. What's going to happen is that a powerful arctic front is going to plow the region tonight and usher in much colder air and in the meantime a strong storm system will be pulling in plenty of pacific moisture and gulf moisture. We are expecting patchy light freezing rain to develop tonight and quickly transition to all snow tonight into the overnight hours.Reguarding low temperatures tonight they should be in the low to mid teens. By daybreak tomorrow low pressure will be located in the Arklatex region and will begin to deepen and continue to deepen in the meantime blizzard conditions will be developing in Oklahoma and Kansas. Strong pressure falls associated with the deepening low will lead to gusty winds close to 40-50 mph so blowing and drifting of snow will be quite likely and visibility's near 0 are going to be common in the heaviest bands. Temperatures will not rise that much tomorrow with temperatures struggling to reach near 20 as heavy snow rates of 2-3 inches per hour will be common and with elevated instability thunder-snow will be possible just about anywhere. With the thunder-snow snowfall rates of up to 4 inches per hour will be possible. Keep in mind also if thunderstorms are able to curl up into the cold air that also locally enhance snowfall so there are at least 2-3 reasons why locally heavier snowfall is anticipated but again it's to hard to pinpoint exactly where which is why we continue to advertise 8-12" plus inches of snow but the map maybe revised just a tad if amounts greater then 12 inches of snow becomes more widespread. Below is what we expect to happen but keep in mind there will be some places that pick up close to 20-24 inches of snow.Even after the snowfall is done wind chill values will be very cold with -10F wind chills likely if not colder this is a very dangerous situation!!

With such a dynamic system one has to wonder about the threat for heavy rain and any severe storms and this storm system this will not be any exception. As blizzard conditions wreak havoc across Oklahoma, Kansas and places north and east - in the warm sector showers and isolated thunderstorms will be plaguing Arkansas, Kentucky into Louisiana , Texas and Mississippi. Widespread heavy rain of 2-3 inches of rain are anticipated with locally heavier amounts are possible where thunderstorms persist. Things get very complicated during the afternoon hours to say the least. It will be moist with surface dew points in the upper 50's to low 60's and marginally unstable. Areas in the warm sector will be highly sheared with 0-1 km storm relative helicitys of over 500 m2^s2 , 200 MB winds over 140 knots, 60-70 knots at 850 mb's. My current thinking is this could be about just as dangerous as what happened on New Years day where there was damaging tornadoes in St. Louis with marginal instability and the supercells where dynamically driven. At this time what I am thinking that along the front a squall line will develop and produce a swath of damaging winds, large hail and a few tornadoes- however if supercells can develop ahead of the squall line and remain discrete long enough, rooted in the boundary layer given the strong low level shear a strong tornado or 2 maybe possible. Here is where things get interesting toward the end of the event that if there is enough moisture leftover in portions of central and eastern Arkansas into Memphis and parts of western Tennessee as the cold air filters in precipitation may end as a wintry mix but little if any snow accumulations are expected. As always stay tuned for the latest regarding these blizzard as we will be starting a live blog tonight.

BLIZZARD To Burry Millions!

2011-01-30T16:40:00.007-06:00

A Particularly Dangerous Situation(PDS) winter storm warning has been issued for the entire Oklahoma City and Tulsa metropolitan areas in advance of a powerful and potentially record breaking winter storm. Though I will focus on Oklahoma's partake in this winter storm, this storm will affect millions in the U.S. stretching from the southern and central plains into much of the Ohio river valley and points northeast.

Now that the storm has come ashore and has been sampled by computer models, both the NAM and GFS are coming around to the idea of significant snow accumulations over much of Oklahoma(generally along and near I-44). The NAM shows snowfall totals approaching two feet in the metro with the GFS showing a little less than that(10-12"). I don't know what to make of the NAM as the 8-12" I'm forecasting now would certainly be detrimental, let alone two feet! The GFS in previous runs was farther east with the heavier QPF which I was suspicious of given the dynamics and track of the storm system. Now the latest 18z run has begun to latch on to the idea of the NAM model and this is concerning but complimentary to my thinking.

NOTE: GFS select graphics at 15z Tuesday...

From left to right, the surface wind speed shows a tight pressure gradient with a 1050 something Arctic high building south out of Canada and a deepening surface low across the Arklatex region. This would likely clock winds over 40-50mph from the north and west and would lead to significant blowing and drifting snow. Blizzard conditions are very likely. The next image shows the 850mb temperatures which are well below freezing. I guess if there was any "good news" it would be that we won't have to worry about an ice storm. At least not for Oklahoma(remember a couple days ago the models had a slower frontal passage and a warm nose aloft; this is no longer the case). Lastly the surface temperature/weather feature map shows deepening surface low over Arklatex with very cold Arctic air spilling south and setting the stage for a major winter storm.

My forecast going is for 8-12" of snow from Oklahoma City and up I-44 into the Tulsa area. You can click here to view the snowfall totals. They will be adjusted given any changes between tonight and tomorrow.

This is a dangerous storm. It is stressed that those in the path of this winter storm take action immediately to prepare for significant disruptions to travel and other aspects of life. Meanwhile, please continue to refer to this blog and our facebook page for the very latest on this winter storm!

Downhill From Here...

2011-01-29T19:01:00.010-06:00

Well above average temperatures continued today from yesterday with highs once more well into the 70's across the majority of the state. The downside to the nice weather has been the very low relative humidity(RH) and the gusty downslope winds that have fed the fire danger. Numerous fires are still ongoing at this hour and there were even fire warnings issued for Logan county earlier this afternoon as a very large grass fire prompted mandatory evacuations.

A cold front which will be the boundary of weather changes will progress across the state this evening and overnight. Temperatures tomorrow will be some 25-35 degrees cooler than what they were today and here in Oklahoma City we'll replace our high of 75 today with 45 tomorrow. This is the initial surge of the Arctic air with the real stuff still considerably farther to the north. Clouds will increase tonight along with gulf moisture ahead of storm system number one that will impact parts of the region tonight and tomorrow. There is even a slight risk of some severe weather across parts of east Texas where increasing moisture will combine with increasing wind shear to produce some hail/wind producing storms. Significant severe weather is unlikely. Here in Oklahoma an increase in clouds and maybe a shower or two across the south and east will be possible.

The big storm, one that promises to be a major weather maker for the southern plains is still offshore at this hour. Computer models continue to be all over the place regarding the details of this winter storm but it's pretty much likely that a significant amount of snow and ice will fall somewhere over the southern plains. As the storm system comes ashore very late tonight, models should be able to sample the storm better and we should start to see a clearer picture on precipitation types and how much. But until modeling on this storm improves, I will neglect to make much reference to any one particular model solution. Winter storm watches have already been issued for western Missouri and southeast Kansas extending southwest into northeast Oklahoma(including the Tulsa metro area). I anticipate the Oklahoma City metro area will be put under a watch sometime tomorrow.

There are a few things I want to point out about this storm:

Someone is going to end up with significant snow and/or ice accumulations. There will be plentiful but highly modified gulf moisture associated with this system transported by a strengthening low level jet. The significant temperature gradient will also act to lead to the development/intensification of a surface low which will track somewhere from north Texas into Arkansas. The dynamic nature of the storm system given inverted 500mb shortwave and 700mb closed low will definitely enhance lift. All models do agree on generating significant QPF for parts of the area in excess of 1-1.25" of precipitable water. With 12:1 snow ratios, someone will end up with a foot or more of snow. Pin pointing this heavier band of snow is nearly impossible at this juncture but we'll know a lot more tomorrow.

Depth and timing of cold air will play a LARGE role on precipitation TYPES. Yesterday's model runs had a slower frontal timing and a shallow warm nose at 850mb. This was very concerning to me in regards to ice. 1" of ice combined with the strong post frontal winds forecast would prove to be devastating leading to widespread power outages and tree damage. Today's runs had a faster cold front and a quick transition to snow but in this case significant blowing and drifting of the snow and poor visibilities will hinder all travel. The timing and depth of the Arctic air will be a critical factor in this storm. Track also is very important. A southerly track would also favor deeper cold but a northerly track and more amplified storm will raise concerns of more warm air getting wrapped up into the storm.

Prepare NOW for adverse weather conditions! Don't wait until the last minute and then decide to take action. The sooner you prepare the better off you will be... It's not about how much snow or ice you will get as even a small amount of ice and snow can cause significant travel disruptions. As I always say, it's better safe than sorry. You can click this link for winter weather safety information.

Our facebook page will also be available with timely updates so make sure you "like" us! In the meantime continue checking back for frequent updates on this developing winter storm!

Let the Model Mayhems Begin but Winter Weather Still Likely

2011-01-28T09:20:00.003-06:00

While the overall threat of a major winter storm is increasing there remains considerable disagreement between the types of precipitation and amounts take for example last nights 0z run of the GFS model. It showed a heck of an ice storm for parts of the viewing area and a heck of a snowstorm for other parts of the viewing area.I am not completely sold on the idea that the heaviest is in Northwest/North Central Oklahoma other factors that need to be worked out like how shallow the depth of the arctic air will be, with the temps be below the 0 degree threshold from the surface threw the critical layers? Either way winter weather looks very much likely Now on the one hand the 6z model did back off somewhat on ice storm and it put more snow in the metro. Here's where things get mighty interesting the 6z run of DGEX model showed widespread 9 up to 18 inches of snow in portions of central and eastern Oklahoma and ALL snow. So that leads to the question why such model mayhem? Each model is analyzing the temperatures at each layer of the atmosphere some see this tiny layer of warm air around 3000-5000 feet and a shallow layer of 32 degrees or lower just at the surface and sees it as freezing rain others show the critical 32 degree mark between the surface and 5000 feet and it would fall as all snow. On top of the temperature complications the other problems include the track of the storm system. the further south it would go would ultimately lead to more snow accumulations and ultimately considerably lower high temperatures. Here's the bottom line. An arctic front will approach the area while a wave moves threw the region. Winter weather appears likely. At this time freezing rain, sleet and snow are all possible until critical thickness temperatures come into better agreement and the track of the storm is more consistent. Any variation in the track being further north or south would ultimately increase or decrease winter weather and winter weather type potential. After this potential snowstorm/ice storm it will be brutally cold with lows approach the single digits and wind chills below zero.It could be way colder depending on any ice pack or snow pack. As always stay tuned we'll keep you updated re guarding this potential winter storm.

A Potentially Significant Winter Storm Is In The Works For Next Week...

2011-01-27T19:25:00.003-06:00

But wait! Enjoy high temperatures in the 70's for tomorrow and even into Saturday. Some may want to take this time however to prepare for what some models are depicting to be a significant winter storm for the southern plains Monday night into Tuesday.

Those with plans this weekend, the weather looks warm(especially on Saturday) and mainly dry. A weak wave and increasing gulf moisture Sunday may produce a few areas of light rain/sprinkles mainly south and east. Monday and Monday night in particular is when the bottom drops out and the weather takes a turn for the worse.The graphic above I should emphasize is by no means set in stone. This is a rough picture/compilation of what the weather models are CURRENTLY suggesting. I've also drawn in the set of possible tracks(or cone of uncertainty) that the storm could take. The GFS has by far been the most aggressive model as far as snow accumulations are concerned. The ECMWF has a track slightly farther south. Nonetheless the large scale weather features ARE indicative of a prolific southern plain's winter storm and this will need to be watched VERY closely over the next several days. There is no doubt in my mind that things are going to change between now and Monday/Tuesday and they are apt to change quickly at that.

The other story will be the COLD. Daytime high temperatures, especially if there is snow on the ground, will be bitter into the low to mid 20's and overnight lows in the single digits and teens. Strong post frontal winds will create wind chill values below zero at times and if there is significant snow or ice it is bound to be troublesome as far as power outages and blowing/drifting is concerned.

We will be updating you all weekend long on this developing weather situation so please check back accordingly for updates.

Springlike WARMTH Followed By Winter's Return

2011-01-26T20:54:00.005-06:00

Yes we've all seen what some of the models and forecasts are showing for next week, the return of cold and perhaps snowy weather. But first we will experience a welcome break from the cold through Saturday with high temperatures well above normal for a change.

Models show nice warm surface ridge expanding to the east from the west with amplified trough across the eastern U.S.( the overall winter pattern so far). This will allow warm downslope flow across the southern and central plains with highs into the 60's in most spots. Some locales on Friday could approach or even top 70.

Low and behold though, winter is not about to give up its hold. The pattern will begin to shift this weekend as shortwave develops underneath surface ridge across the southwest. Northwesterly flow developing out of western Canada and into the plains will drive cold Arctic air to the south by Sunday and deepening Monday and Tuesday. At around the same time models are depicting shortwave across the southwest amplifying and ejecting east into the southern plains.

From left to right the Euro 850mb temperatures and surface weather pattern shows Arctic air pouring south on the back side of an amplifying/deepening surface low across Arkansas 12z Tuesday. The GFS 500mb heights to the right shows nearly closed inverted low approaching the area around the same timeframe. The Euro is a little stronger with the amplification thus bringing in warmer air ahead of the system(this tells me precip will start as liquid and transition to freezing/frozen). On the other hand, the GFS has cold air already in place with precip quickly transitioning to snow. Just to put things in perspective, the 18z run of the GFS this afternoon had 12" of snow in Oklahoma City by 06z Wednesday. However it should be noted that prior runs had much less snow if any so this is only a very recent development. The European has been the most consistent of the two models so far and so I've put more trust in the ECMWF for now. It will be interesting to see what tonight's 00z runs depict.

Bottom line, is that it will be turning much colder next week and there is a likelihood of wintry precipitation early on with a developing potential of a winter storm somewhere in our vicinity. I've been aware of this trend for a few days now but have been reluctant to say much about it due to models in the past hyping something up only to have a much weaker system much closer to the event. Stay tuned!

Several Shortwaves, Lack of Moisture.

2011-01-22T19:35:00.002-06:00

A fairly potent shortwave will pass through the state tomorrow but moisture will be limited so precip chances are fairly slim. The highest chance for any light snow or flurry activity will be to our north and east and even there accumulations look little to none unless you live across north and west Missouri where a winter weather advisory is in effect for 1-3" of snow. Otherwise some cloud cover and colder temperatures compared to today will be the main impacts for Oklahoma.

With a progressive northwesterly flow regime in place across the southern plains, several fronts and shortwaves will traverse the area throughout the week. However moisture will remain limited so the chances for measurable precipitation are very low. Temperatures in the 40's and 50's will be expected for afternoon highs. There are some indications in the longer range models that cold Arctic air will return to the area by next weekend.

I've been looking ahead to next month and it appears that a cold/active weather pattern will persist for much of the country. Definitely not your typical La Nina impacts. I'm really looking forward to spring and severe weather season... there is a lot planned!

Fast Moving Winter Storm To Create Travel Probelms Tomorrow!

2011-01-19T17:39:00.003-06:00

Winter weather advisories are in effect for much of Oklahoma including all of central Oklahoma. There are even winter storm warnings for the Tulsa metro area. The broader picture shows some type of winter weather advisory or warning for a large part of the central and southern plains into the Ohio river valley. This is all in advance of a quick hitting but potent winter storm that will affect Oklahoma tonight and for the first half of Thursday.

Because the system will be a progressive one, I am not expecting a major winter storm out of this. Snowfall totals will average between 1-3" in most areas by tomorrow afternoon. However addressing the possibility for heavier snow bands given the strong frontogenetic forcing that will be in place, higher snowfall totals are reflected for north central and northeastern Oklahoma.

Precipitation will begin late this evening across the north spreading south overnight. Initially, dry low levels and above freezing temperatures in the middle layers of the atmosphere will make freezing rain and sleet a possibility especially near and south and east of I-40. As Arctic air rushes in behind cold front that will traverse the state late tonight/early tomorrow morning the wintry mix will quickly transition to snow. Therefore, I'm not expecting significant ice accumulations with generally less than .10".

Because the peak of the event will occur during the morning hours on Thursday, hazardous travel conditions are quite likely. There is a good possibility of school cancellations and very slow travel for the morning rush hour. As system quickly departs Thursday morning, snow and ice will come to an end from west to east by midday. Cold and blustery conditions will prevail however, with highs only in the 20's and 30's.

I thought I'd mention there is yet another system we are watching for the late weekend/early next week timeframe. Both the Euro and GFS show a more significant system affecting the southern plains and with plenty of cold air around this could very well be our next winter storm...perhaps major. Please check back for updates regarding this potential.

Winter Weather Still looking Likely

2011-01-18T11:38:00.000-06:00

What a difference a few model runs make. Earlier in the week forecast models were forecasting a decent winter weather event for the region but over the past 48 hours some.. not all...have backed down significantly. The one thing that must be stressed is that this is still 2 and half to 3 days away and models will still do there "cha cha cha" and flip back and forth. Here's what makes winter weather forecasting difficult, the precipitation starts as snow. As it falls, it hits a layer "above" freezing between 3600'-8300' THEN, it goes back into freezing air. If it has time to refreeze, it falls as sleet. If it does not refreeze, it hits exposed surfaces as water and a shallow layer of temperatures below freezing the it forms a glaze hence freezing rain. Now IF the critical layers are all below freezing it will be all snow. Below is 2 forecast models the nam and the gfs.

First model is the gfs second model is the nam model forecasts on accumulated snow buy Friday morning. now amounts look light-especially on the nam but why? By Thursday morning the nam is breaking out precipitation and the 540 line (rain/snow line) is entering into central Oklahoma by then 850 MB temps are below freezing so it should all be snow however it's also showing by 1 pm that only 1/10th inch qpf is left and judging by how poorly the nam did during last event and how poorly it's doing now we disguard it while the gfs is showing heavier precipitation. So here's the bottom line- there will still be snow...at the onset of precipitation there will be a period of sleet and/or freezing rain and there's still alot of questions that need to be answered such as how quickly the cold air arrive and how heavy the precipitation will actually be and we may have to end up relying on the hrrr model when it's all said and done cause it did way better then the other models did for the past winter weather event. Another thing that needs to be stressed is that depending on how things play out there will always be potential for 1 or 2 bands of heavier precipitation to develop that's where the heaviest of the snow is going to be but right now it's is impossible to determine where they will set up at. However this may not be the last event as the European model has been interesting to say the least for next Monday but that will be discussed more towards the weekend.

Wintry Mix Of Precip Types Thursday

2011-01-17T18:58:00.004-06:00

We are closely monitoring a storm system on Thursday that is now looking like it could bring a hazardous winter storm to Oklahoma.

It is looking more likely that a wedge of above freezing temperatures in the 850mb layer will be apparent, especially near and south of I-40. With surface temperatures expected to be below freezing ice is the likely precip type and while models are showing less than .25" of QPF in these areas, in terms of ice that is fairly significant and would fit ice storm criteria. Farther north snow will be more likely with mid levels cooler. Current runs would suggest 2-4" of snow would be possible across north central Oklahoma. Gusty winds may lead to some blowing and drifting of snow which will undoubtedly lead to travel problems.

Fairly progressive nature of the storm will probably prevent this from being a more significant storm. However it should be noted that any changes in track or speed of this system will have significant implications on who will see what and how much. We'll keep you posted!

Watching Mid-Late Week...

2011-01-16T19:17:00.002-06:00

A cold front passed through the area overnight last night bringing chillier air back into the southern plains. The affects from this front will be short lived however as southerly winds return tonight allowing temperatures to warm into the 50's/60's for Monday. There will be yet another frontal passage Monday night/Tuesday morning with colder air filtering back into the area.

Our focus has been on a developing weather system for Wednesday and Thursday that could bring significant winter weather impacts to the area if things come together just right. Both the GFS and European now show a decent shortwave and associated surface low impacting the area Wednesday night and Thursday but they differ on the depth of cold air and precipitation types. The GFS is more aggressive with cyclogenesis over the southern high plains leading to warmer air being pumped north across a shallow Arctic air mass at the surface. This scenario would favor ice with little in the way of snow. The European is colder and deeper resulting in a quick transition to all snow. For now I will side with the European as it has been the most consistent but will not neglect the GFS as things could easily go both ways.

It is too early to get an estimate of how much of any type of precip will fall. Will have an update tomorrow.

Respite From Cold Weather Pattern...For Now.

2011-01-14T21:16:00.006-06:00

Temperatures Thursday afternoon rose above freezing in Oklahoma City for the first time since Monday evening. That means we spent 84 hours+ below the freezing mark!! Temperatures today were even warmer with many locations approaching if not exceeding 50 degrees. Responsible is the shift of the Arctic surface high to the east and southerly return flow on the western periphery of the ridge.

Another cold front will progress into the state tomorrow leading to a wide range of temperatures. 40's to the north of the boundary will be common but temperatures well into the 50's(even some 60's south and west) will be present to the south. The front gains momentum on Sunday as developing weather system up north shoves the front south. Highs on Sunday will return to the 40's in most spots(some 30's across the north). Models develop area of low pressure along the front Saturday night and Sunday however temperature profiles will be only marginal for any wintry precipitation and expect no significant impacts as better lifting mechanisms will be located south and east of our area.

Looking a head to next week the synoptic flow pattern will be progressive with no blocking features in place. This is largely due to a recently positive NAO. The persistent and anomalous 500mb trough across the east is no longer with no upstream blocking. This means that despite a negative AO and plenty of cold air up north(and there will be several fronts next week), the core of the cold will focus well to the north and east of the southern plains say from the Midwest into the Great Lakes and upper New England next week. The GFS depicts this very well. However the Euro(or ECMWF) shows the development of yet another southern branch system late next week taking on some similarities to the system that developed last week and brought the winter storm to much of the south. Coincidentally it also brings a renewed Arctic air mass into the area just in time. The temperature profiles look ominous as the air mass will be shallow favoring a setup for ice. On the other hand the GFS has a much less amplified system and is also much warmer. Due to the varying solutions between the GFS and Euro, I will neglect to make any conclusions on a storm next week.

Major Southern Winter Storm Underway! LIVE Blog

2011-01-09T12:46:00.026-06:00

UPDATE- January 10th 2:53 pm CST

A wind chill advisory has been expanded into the Oklahoma panhandle. While there is still some snow in central Oklahoma - it's generally light and radar trends suggest the heaviest of the snow is moving into southern Kansas. Roads will still be icy as temperatures are very close to the critical 32 degrees. Wind chill advisories will be issued later- check back into the home page as it will updated with current advisories shortly. This concludes the live blog for this winter weather event. Be sure to check the video and picture's area for our footage from this event later on in the week.

UPDATE- January 10th 2:05 pm CST

Wind Chill advisories have been added to portions of Oklahoma including Roger Mills, Dewey and Custer counties.As said before- more wind chill advisories are going to continue to be added. Elsewhere east of Oklahoma City metro snow is continuing to fall. Places like Moore, Chickasha, your in the thick of things however snow is ending in Anadarko. This band of snow extends from near Anadarko all the way into Tulsa- 1-2 inches of snow will be likely as this band moves off to the east/northeast.

UPDATE- January 10th 12:26 pm CST

An area of light to occasionally moderate snow is once again developing- in this particular band- it extends from just east of Anadarko northeast into Moore and highway 66 near Chandler. Movement on this band is to the northeast- a quick 1/2 to 1 inch will possible within this band and 1 more band is developing near Hobart to near Carnegie and also moving to the northeast. Between Woodward and Enid there's another area of moderate to heavy snowfall is occurring with accumulating amounts of 2-3 inches possible. In addition a wind chill advisory has been issued for Pawnee and Osage counties for wind chills below 0 likely. I anticipate more wind chill advisories to be issued later today.

UPDATE- January 10th 11:32 am CST

Zack is reporting to be from what he can tell he picked up a quick 1/2 inch of snowfall. As of now that snowfall has dissipated but there's still snow nearing Shawnee. Keep in mind temperatures probably will not make it above freezing cause of the clouds and additional snowfall is possible and again with temperatures not making it above freezing some accumulation is possible.

UPDATE-January 10th 10:25am CST

An area of moderate snowfall is encroaching the Oklahoma City area. Areas most effected by this band of moderate snow will be Oklahoma City metro, Moore, Union City is getting hit, Norman may get clipped also.This area is also under a freezing rain advisory along with southern Oklahoma until noon. Elsewhere snow is developing just west of Woodward, Oklahoma into Buffalo and generally is moving east. This snow is occurring behind a secondary cold front. Road travel is going to be very tricky as temperatures are below freezing. Elsewhere the snow that plagued southwest 1/2 of Arkansas with up to 10 inches of snow is starting to wind down in the Carolina's. Stay tuned as more updates will be made as needed.

UPDATE-10:51pm CSTFreezing drizzle is falling across much of central Oklahoma. With temperatures well below freezing, slick spots may develop overnight. As lift in the cloud layer increases with the approach of the next system, precipitation will increase once more. 1-4" of snow can be expected overnight and tomorrow for areas north of I-40. Lesser amounts farther south. You can get the latest on road conditions and school closings(there have been several closings coming in) on our homepage. http://www.oklahomaskies.net/

UPDATE- 8:10pm CST
Snow.. heavy at times continues across central and eastern Arkansas- there's a band in particular that has me interested- it's located along a line from just north of Sheridan, Arkansas *Grant County* into Jacksonville, Ar *Pulaski County*. I just had white out conditions at my house. To give you an idea of how heavy it is so much drifting it took out 90 percent of the snow on the roof and the snow has completely recovered the roof. There is a potential for snowfall rates of up to 2 inches per hour as it moves east/northeast with some thunder and lightning possible also.

UPDATE- 5:55pm CST
Snow has continued to taper off across Oklahoma and much of northeast Texas and has bombarded Arkansas and Mississippi. Some lightning strikes have occurred within the heaviest bands. Within these heavy bands that lightning is occurring snowfall rates of 3-4 inches per hour are likely. As temperatures continue to fall roads will continue to be snow and ice packed- travel is not recommended.

UPDATE - 3:59pm CST
Snow will taper off in most areas in Oklahoma through early evening as upper low across northeast Texas shifts east. However snow will increase again to the north and west as another system approaches from the northwest. Temperatures in most locations are within a few degrees of either side of 32 and some slick spots are possible in areas where heavier snow accumulations resulted today.

UPDATE-3:51 pm CST
I-30 shutdown SW of Arkadelphia, Arkansas, due to 6 tractor trailers and several cars in accidents!!

UPDATE- 3:16 pm CST:
Both Zack and I are both receiving a heavy wet snow with Zack reporting accumulations up to trace but still accumulating and I have received up to half inch also with roads becoming snow covered already. The snow is blowing and drifting implying there will be reduced visibilities in heavier bands.

UPDATE- 2:27pm CST:
Snow is just now entering into downtown Little Rock and reports are that while there not big flakes but it's coming down hard visibility is only 1 mile. Travel is not recommended as temperatures are below freezing accumulations are likely to start within 2-3 hours with storm totals of 4-6 inches locally more!!!

UPDATE - 1:54pm CST:
Winter Weather Advisory has now been expanded to include the counties of Seminole, Hughes, Murray, Pontotoc, Coal, and Carter in southeast Oklahoma. Light to occasionally moderate snow will affect the area through the evening.

UPDATE - 1:33pm CST:
Light snow and sleet is now falling once more across the Oklahoma City area. No accumulations are being reported at this time and travel problems not anticipated as temperatures remain above freezing for now.

UPDATE - 1:12pm CST:
Looking at some of the road conditions across the region if your in Pine Bluff headed towards Little Rock forget traveling it's snow packed. From I-40 southeast towards Mississippi all snow packed- further to the south there's slushy roads and further southwest towards Texarkana there ice covered. Please do not travel as there have been fatal accidents already. Denton, Texas threw Collin, Texas ice and snow covered. New winter storm warnings do re-include near Dallas to the northeast.

Stay tuned for new updates as this dangerous winter weather situation unfolds!

Main Post - issued at 12:46PM CST:
A significant upper level storm system moving across central Texas is bringing significant snow and ice to much of the south.
A large and slowly expanding precipitation shield was in progress to the north and east of the upper low. Heavy snow is falling across much of the DFW area with fatal accidents being reported. Snow is also spreading into much of southeastern Oklahoma and extending northeast across the southern half of Arkansas. Plentiful low level moisture is being pulled atop a low and mid level Arctic air mass and resulting in precipitation falling mainly as snow. However sleet and freezing rain is also being reported in some areas. Temperatures are below freezing in these areas resulting in snow and ice accumulating on roadways. This is a dangerous weather situation.

Here in Oklahoma snow was expanding across southeast and south central Oklahoma. The most persistent snow was occurring generally south and east of I-44, but snow will likely occur as far north as this interstate as well. Light snow and sleet was already reported earlier this morning in Oklahoma City. Winter weather advisories are in affect for far southeast Oklahoma at this time where 1-3"+ may fall.

This is the start of a live blog. We will be providing frequent updates on travel conditions, closings, etc throughout the day so it would be a good idea to bookmark us. Stay tuned!

Winter Storms To Slam Parts Of The Southern Plains!

2011-01-08T20:05:00.003-06:00

Two storm systems are taking aim at the southern plains Sunday into Monday. Both systems will be capable of producing significant snowfall in parts of Oklahoma. The first system will arrive late tonight into tomorrow and is currently getting its act together across west Texas. Precipitation was already developing across Texas, and will continue to become more widespread overnight as moisture continues to increase and lift from the upper level system approaches with movement to the NNE.Winter storm watches and warnings cover much of the lower Mississippi River Valley and points east across much of the south in anticipation of a major winter storm for these areas beginning tomorrow. Upper level low will track across Texas with surface low near the coastline pulling in plenty of gulf moisture over an Arctic air mass at the surface. A variety of winter precip types ranging from freezing rain to snow is likely with snow more likely farther north and ice farther south. Models show significant snow accumulations for the aforementioned areas ranging from 4 to as much as 8". Isolated totals of near a 12" will be possible given the high liquid to snow ratio.

While it would appear that the models are in agreement on keeping the biggest impacts to the south and east of Oklahoma, any deviation in storm track will bring significant forecast changes. Areas along and south of I-40 in Oklahoma could receive higher snow accumulations(especially southeast) then what is currently forecast as it is possible the storm could track farther north. We will be watching this closely tonight. For now, far southeast Oklahoma stands the highest chance at significant snow accumulations from this system where winter weather products have been issued.

As the first system departs Sunday night, another northern branch system will follow quickly on its heels Sunday night into Monday. This system will bring significant snow accumulations to much of Kansas where there are winter storm watches currently in place. Snow accumulations of 2-4" will also be possible across much of northern and western Oklahoma(primarily north of I-40 and northwest of I-44) with this system with lighter amounts of 1" or so farther south. A stronger Arctic front will arrive Monday and post frontal winds could also lead to blowing/drifting of the snow. Hazardous travel is possible.

After the snow, a prolonged period of subfreezing weather will occur through Wednesday. Highs each day will fail to make it above freezing and wind chills will likely be near or below zero at times.

The Polar Plunge!

2011-01-06T20:17:00.004-06:00

Big weather changes are still on tap beginning this weekend. Temperatures tomorrow across the sooner state will remain rather mild for early January with statewide highs topping out in the 50's northern and central to near 60 south. The weekend will actually start out dry and still mild as the storm system we are watching for this weekend looks to be a lot slower and taking a track almost far enough south to keep much of the precipitation south of our area. Sunday this system will begin tracking across Texas with light precipitation mostly near and south of I-40. The initial surge of Arctic air will have passed through Sunday morning and so temperatures while marginal may be cold enough to allow a wintry mix across central Oklahoma with a cold rain southeast. This same system could bring a swath of heavy wet snow across parts of Arkansas and the lower Mississippi river valley Sunday night as colder air deepens and works with the plentiful moisture available.

The 12z run of the ECMWF(also known as the Euro) shows the two systems we are watching as they are situated now along with the projected tracks. Note system 1 is still well offshore with the secondary system still in the Gulf of Alaska but will head southeast towards the area by Monday.

System 2 is the one that will be most favorable for accumulating(perhaps significant) snow across Oklahoma. Arctic air will begin deepening Monday with highs likely not breaching 32 degrees in most spots. It appears that we will be in the favorable exit region of the jet streak along with frotogenetic forcing which should provide enhanced lift for widespread precipitation in the form of snow. While it is likely that much of the state will receive accumulating snow, the highest chances of significant accumulations as it appears RIGHT NOW will be across northern and western Oklahoma where amounts of 2-5" will be possible. Elsewhere 1-3" are generally expected. Strong post frontal winds will likely lead to blowing and drifting of the snow and travel problems are possible. Will continue to monitor future model runs on the possible winter storm.

Of equal concern is the prolonged period of subfreezing temperatures that is likely to occur for much of next week. Cross polar flow will continue to pour bitterly cold Arctic air into the southern plains with highs likely in the teens and 20's and lows in the single digits(some lows near or below zero over northern Oklahoma will be possible). Strong winds will create sub zero wind chill values which will pose a danger to those spending any length of time outdoors. Make sure you spend the next couple of days preparing for this Arctic blast like making sure pets will be comfortable in this type of weather and making sure your home and vehicle is adequately prepared for the weather. Visit this link for more information on vehicle and home winter weather safety.

Medium and long range models show that surface high may shift east late next week as several systems cut through. This will allow brief warm ups in between systems only to be followed by surges of bitterly cold air. This pattern of temperature extremes will likely exist for the next couple of weeks as plenty of Arctic air will be present across Canada. Stay tuned!

Winter Storm Still on the Table

2011-01-06T11:17:00.004-06:00

Good morning.Hope you all have had a wonderful week so far because a major weather pattern change is fixing to take place as early as Saturday. Over the next couple days warmish temperatures as high as the upper 50's to low 60's will reside in the area both today and Friday before an absolute powerhouse of a front moves threw the region. Behind the front arctic air is going to be arriving- but the questions are how much moisture is involved, of that moisture how much is liquid , how much is frozen, and how much moisture will be left over. According to the new 12z gfs a decent band of snow sets up Sunday morning in southeast Oklahoma into west central into parts of central Arkansas and by Sunday night 2 to as much as 6 inches falls into Mississippi and Alabama, but don't be discouraged for the rest of Oklahoma. Tuesday afternoon 3-5 inches of snow is showing up, but again this is just the gfs model. Now if you believe the gem model most of the moisture is gone before the freezing line gets there but by hour 96 the freezing line is into central Oklahoma with .15 inch liquid equivalent and by hour 102 the freezing line is in central Arkansas with .25 liquid equivalent and still .10 inch liquid equivalent and with a 10:1 snow ratio that's still roughly 4-5 inches of snow but it's slower then the gfs. The devil is in the details as to exactly how far south the low goes but the bottom line is the further south the low goes say into extreme southern Louisiana say for example as far south if not further south like say interstate 10- the cold air would be in place but we wouldn't have much moisture. If low can get somewhere around interstate 20 not only would there be plenty of moisture to play with but the cold air would already be in place. Looking a tad beyond this after the snow the arctic hounds will be unleashed for at least 4-5 days with HIGH temperatures near between 20 and 25 with lows in the single digits and dangerously low wind chills. Again depending on how much of a snow pack temperatures could go even colder. As it stands right now bottom line is there is snow potential with significant accumulations possible depending on the track, and bleepity bleep bleep bleep cold air is coming. More updates will be coming as things become more clear so stay tuned!!

Get Ready...

2011-01-03T18:40:00.004-06:00

There has definitely been a lack of blogging on my part and being that I've been out of school for the past week and a half there is really no excuse. But rest assured I'm not neglecting this blog or the website for that matter there has been a lot of family drama and other personal issues that have been holding me back for awhile. Maybe it's a lack of motivation or weather as well. December was a fairly nondescript month besides the roller coaster temperature ride and then the damaging tornadoes that affected far eastern Oklahoma(and numerous other states) at the very end of the month. Click here for the storm reports from that day.

It's a new year and a new beginning for me as I set to debut my career as a storm chaser/meteorologist and graduate in May. There is A LOT planned for the upcoming storm season and the off season months have included me making sure I'm out there much more often this year with better luck. This is just the beginning.

Bringing you back to the weather world, quiet but cold weather has ringed in the new year for much of Oklahoma. A weak frontal boundary was progressing through the area and practically nothing more than a wind shift as the air behind the front is not much colder than the air ahead of it. There will be several fronts this week, each progressively stronger. Temperatures will attempt to moderate by the weekend but it won't last long.

The large scale pattern has seen anomalous height rises over Alaska and western Canada as a ridge pokes through and this will allow bitterly cold air to build. The stratosphere is undergoing another warming event this time in the 10mb layer and possibly induced by the buildup of SO2(sulfur dioxide) created by the volcanic eruptions over the last few years. The stratospheric warming this winter, low solar activity, and a persistently negative NAO along with the upward motion contributed to the 2010 hyperactive hurricane season has overwhelmed the ENSO event(La Nina) creating a complex and in some cases unpredictable weather pattern this Winter. Anyway, this warming of the 10mb level of the stratosphere has some major complications for our weather pattern this month and will set to drive bitterly cold air over the north pole southeast across Canada and much of the U.S. The GFS has been in no secrecy about this showing and quoting my local NWS "unprecedented cold" penetrating deep into the U.S. Some of the previous GFS runs were showing HIGH temperatures near and BELOW zero as a nice 1052-1058mb high comes sliding down out of western Canada. This may be overdone to some extent but given the negativity of the AO and the large scale drivers that are in support it would not be completely out of the question. If this type of cold does commence this far south, it would be of historic proportions.

In a pattern setting up like this the bar is raised for snow and ice concerns and they may develop as early as THIS weekend. The models are showing a series of weak upper waves ejecting from the west along a sharp thermal boundary draped across the area late this weekend/early next week. Arctic air will be nearby but models differ run to run on the southward extent of this boundary and exact track of systems but the general idea is that the threat of wintry precipitation is increasing. As bitter cold settles in the following week there will undoubtedly be more opportunities for snow or ice or both. This is something that warrants close attention and we will be updating about it all week long so stay tuned.

Strong tornadoes possible today!!

2010-12-31T08:01:00.001-06:00

It was a rocky night for some people last night as supercell thunderstorms erupted from southeast Oklahoma into northwest Arkansas where reports of a tornado destroyed a mobile home and 2 barns occurred in Cincinnati, Arkansas (a town in Washington County, Ar.) other reports included golf ball sized hail in Crawford County, trees uprooted, damage to outbuildings, several homes were damaged in Indian Point, Missouri so these storms still mean business. For today with regards to the severe prospects here's the current day 1 outlook from the storm prediction center out of Norman, Oklahoma.

For the most part I can agree with that although I would put a 10 percent area for the Eastern 1/3rd of Arkansas and Western Mississippi where storms that pop up there will have more time to be discrete and tap into rich moisture and an increasingly unstable airmass. A couple different tornado watches are out with the most recent watch being for roughly the northern 1/2 of Arkansas, southeastern half of Missouri and extremely west central Illinois. With regards to instability despite the cloud cover MUcapes of 500-1000 j/kg are already being noted in the warm sector.

I am concerned though from southeast corner of Arkansas into western Mississippi where visible satellite images shows clear skies for the most part and this will further destabilize that atmosphere even more. With bulk shear of 50-70 knots, coupled with current storm relative helicitys between 500-600 this area is strongly sheared. Of note also is the strong 0-1 shear of 40-45 knots it'll produce a window of opportunity for a couple strong tornadoes. Later in the day however as hodrographs go from wickedly curved to more linear the tornado threat will decrease significantly and storms should transition into qlcs with a threat for wind damage- given the strong wind fields significant wind damage is possible. and hail up to 1 inch although in the stronger updrafts a tad bigger.

La Nina's Reign On Pattern Begins...

2010-12-27T20:35:00.010-06:00

The first in a series of large scale troughs mid-late week will signal the end of a pattern dominated by blocking and a beginning of a new progressive weather pattern featuring troughiness across the west and more ridging over the south and east. This is a typical La Nina pattern that has been inevitable since May when the first signs of dwindling sea surface temperatures in the pacific emerged. The hyperactive hurricane season was the wild card for this winter calling for a cold opening and this has verified greatly. November and especially December were significantly colder across the south and east due to an unfathomable amount of upward motion across the Caribbean created by the record warm sea surface temperatures. This imbalance can only be smoothed out by bringing the colder air from the higher latitudes southbound and what we saw over the last month or so is an example of just that. A brief stratospheric warm up and a blip or feedback lag in the QBO created a negative AO combining with the decadal negative phase of the NAO which in turn created a polar connection across the east dominated by a resurgence of blocking similar to last winter.

This pattern can not last all winter and with the trough across the west no longer hanging back, it will begin La Nina's "reign" on our weather pattern with troughs coming and going this week pumping warmer air into the east and pushing the colder anomalies across the north and west(similar to the beginning of November which I alluded to as a sampling of the overall Winter).As the cold redevelops over the pole and blocking breaks down the AO will respond by becoming positive by early January. A positive AO inflicts lower pressures over the pole and keeps the northern U.S. colder while the southern and eastern U.S. is warmer. There are some indications that height rises will return to Alaska and an attempt to warm the stratosphere again(possibly volcano induced from all the recent eruptions even though the main affects typically lag by a few months/years). This would bring widespread cold mid-late month. Otherwise La Nina is the main driver during the heart of Winter.

Bringing you back to this week here is the 18z run of the GFS showing the 500mb heights 12z Friday morning. That is one massive trough and you can also see the ridge being pumped into the east. The negative tilt raises the concern for the possibility of severe weather somewhere in our vicinity but details remain fuzzy at this time due to the inconsistency of the models.

Track and timing will also be important as a slower system and a shift to the south will bring a threat of wintry weather to our area just in time for the New Year. It is certainly something that we will continue to monitor this week. Stay Tuned!

New Years To go out with a bang!!!

2010-12-25T07:44:00.003-06:00

First of Merry Christmas from all of us at OSN!!! Things didn't quite pan out the way we wanted to for snow. However that doesn't mean New Years won't go out with a bang because that's exactly what the GFS model at least is showing. That bang is an absolute powerhouse of a trough that's going to moving into the area by next week more on that in a minute. Untill that happens however high temperatures should range from the upper 30s to low 40s with lows in the upper teens to low 20's that's when the dirty warm up takes place. What I mean by dirty warm up is an increase in humidity and temperatures without any sunshine. Onto the trough- yesterdays 12z run of the gfs was the most dramatic solution.

IF this was to verify there would be a massive outbreak of severe storms and tornadoes across the southern plains and lower Mississippi Valley. Again the GFS model has backed down on the strength and timing of the system however still shows 60 plus dew points across the region with very strong jet dynamics- take for -example the 6z gfs model from last night- right entrance region of a 90 plus knot jet, low level jet cranking as high as 50-60 knots, and 250 mb winds as high as 120 knots. Right now here is the bottom line: A dirty warm up is going to take place during midweek. A warm, moist and unstable air mass is going to be in place for a powerhouse trough. There will be strong jet dynamics with this. Severe Weather will be possible as early as Friday with all modes of severe storms possible. There are still some timing issues as to be expected this far out of the way. Just a little teaser also- this is what the 6z dgex shows at the same time of possible severe weather. Keep in mind a more northerly track would put the area in the warm sector- and a more southerly track would mean a chance at wintry weather as suggested by the 6z DGEX. We'll keep your updated reguarding this potential severe weather/winter weather.

Have a Merry Christmas everyone and keep bundled up!!

Last Minute Christmas Storm(Again?)?

2010-12-21T18:05:00.007-06:00

Some interesting developments in the models today regarding a developing storm system progged to bring a variety of weather/precip types to the southern plains Thursday-Friday. A notable shift in projected storm track to the south has been perceived today which raises the concerns for wintry weather getting involved in the forecast. The European model(also known as the ECMWF) has a more robust low in its 12z run cutting off from the main flow over the southern plains. This solution is the farthest south of the models but also the most bullish of them as well. I don't believe with a progressive pattern being depicted overall that the storm will become a closed low across Texas. The NAM and GFS runs have a more plausible scenario with a more progressive system and a surface low tracking just south of the red river. In either scenario it does NOT appear at the current time that a winter storm is in the makings.... at least not for Oklahoma. However as cold air arrives on the backside of this system and the entire column begins to cool, a transition to a bit of snow will be possible mainly from areas along and north of I-40 Thursday night and Friday morning. Snow accumulations if any will be light. It is to be noted that typically a storm of this nature would normally produce a prolific winter storm for Oklahoma, BUT it currently appears that very warm air will become entrained into the storm initially preventing such an event. This is something that warrants close attention though.

Of equal if not greater concern is the potential for widespread and locally heavy rainfall primarily along and east of I-35. Gulf moisture will get involved in this system combined with isotropic lift and warm air advection(initially) and this will allow for a beneficial rainfall for many. While instability will remain less than adequate for severe weather, a few thunderstorms will be possible in the warm conveyor belt portion of this system primarily south of I-40 and east of I-35. As it currently stands, Saturday(Christmas Day) looks dry.

Below is our graphic compiling Christmas Eve and Christmas Day. Giving that there will be a lot of travel plans in place around the big holiday, it is very important that you check back to this blog for frequent updates leading up to this event as things are apt to change... and quickly at that. Stay tuned!

Total Lunar Eclipse Visible From N. America Tonight!

2010-12-20T19:53:00.004-06:00

Something that has not happened since 1638 and not to happen again until 2094 -- A total lunar eclipse on a winter solstice! The graphic above is from the NWS here in Norman showing the time line of the event from the Umbral phase to Totality. The next Lunar Eclipse will occur in 2014.

Unfortunately widespread cloud cover associated with a weak surface low will hinder viewing prospects significantly across the southern plains. Donny Cook from Jacksonville, AR will attempt to do a time lapse of the event but it's all weather permitting. Stay tuned!

Winter Storm To Bring Accumulating Snows To S. Plains

2010-12-16T21:48:00.002-06:00

Winter weather advisories are in effect for all of the Oklahoma and Texas panhandles in advance of a fast moving but potent winter storm system emerging from the southwest.

While the 500mb levels indicate low amplitude the 700mb level reveals a sharp trough with short wavelength. Radar shows widespread virga(precipitation that is not reaching the ground) over much of north central Oklahoma and into the panhandles. This is indicative of mid and upper level moisture however the lower levels per forecast soundings are quite dry. It is expected that as the profile moistens tonight and precipitation begins to increase in intensity and coverage, precipitation will begin reaching the ground. 850mb temps will be between 0 and -10 degrees and surface temperatures around freezing which will support snow at the entire column.

The heaviest snow accumulations will be found in the panhandles where frontogenetic lift and convective features will enhance precipitation rates in this area. The HRRR and RUC models show a large band of snow in this region with resulting 7-10" of snow. This may be a little overdone but it isn't out of the question that some locales north of I-40 in the panhandle region could receive 4-8" in the deformation zone.

As the shortwave traverses farther east both 700mb and 500mb structure becomes less organized indicating a weakening system by the time it reaches Oklahoma. However modeling insists a narrow band of 1-3" snow accumulations could result in areas west of I-35 along I-40. Winter weather advisories are currently not in place for the Norman county warning area at this time. Snow will end west to east during the evening Friday as system departs and weakens further. Again a winter storm for Oklahoma is not anticipated but those traveling west bound on I-40 into the Texas panhandle may want to stay abreast of the weather conditions in this area. Little to no impacts to travel are expected for the Oklahoma city area.

Storms Tracking Farther South This Week & Next

2010-12-13T20:55:00.006-06:00

The monster of a storm that brought a blizzard to much of the Midwest and Great Lakes region has now departed leaving a large fetch of Arctic air in its wake. This air mass has plowed deep into the Gulf of Mexico with a record breaking hard killing freeze anticipated tonight across the coastline and even for the Florida Peninsula.

Here in Oklahoma, temperatures in many areas this morning were their coldest of the season yet with single digits and teens across northeast Oklahoma and teens to around 20 here in central Oklahoma. Lower to middle twenties were found elsewhere. Deck of mid and high level clouds kept the temps up some across central and south preventing us from reaching our expected low of 15 at the airport this morning. Temperatures will be cold again tonight and chilly tomorrow afternoon with air mass only slowly modifying. There will be a temperature gradient pronounced across the state this week with deeper colder air mass hanging on to the north and east and a more shallow somewhat milder air mass across the south and west. Another frontal intrusion will make its way across the area mid-late week.

The storm track shaping up for the next couple weeks is one that with the presence of cold air will make for an interesting weather situation for us in the south and east. The first of two weather systems I am monitoring will arrive this Friday for the southern plains.

A low amplitude shortwave trough will emerge from a weak southern branch mid-late week amidst a blocking regime with the teleconnecting lows across the northeast and northwest. While the air mass for late week does not appear to be purely of arctic origin nor very deep it does appear cold enough with the combined cooling affects of the upper low itself to support the possibility of snow. There doesn't look to be a lot of moisture in place to support significant accumulations, however accumulating snows are a possibility and any deviations in strength, track, and moisture quality will have huge implications on what and how much. As it appears right now though impacts look to be relatively trivial, in a way similar to the snow event we had last Tuesday. Again this will be monitored closely.

Now the question that always seems to be addressed during this time of year is whether or not we will have a white Christmas. To be honest here in Oklahoma our chances are less than 5-10% respectively.The farther north you live, obviously the better chances of your ground being white not brown Christmas morning. Last year we dealt with a blizzard which gave us a snow depth of over a foot in some locations. Interestingly enough, the pattern leading up to Christmas has all the similarities of the pattern that produced our white Christmas last year which included the amount of blocking we are seeing along with the negative AO/NAO. The latest runs of the GFS have not been nearly as enthusiastic with a Christmas snowstorm as compared to its previous runs, however the ECMWF sure looks interesting and a lot can change between today and Christmas day so as always stay tuned.

Arctic Blast Coming!!! Isolated strong storms possible

2010-12-11T08:29:00.000-06:00

Good morning y'all. IF you think that this past week was cold get ready for even cold air as a strong cold front is pushing threw the region. Ordinarily we would be concerned about a severe weather outbreak cause of the strong wind fields regarding this system but winds are also changing with height (IE surface south winds, winds at 5000 feet or 850 mb and winds at 18,500 feet or 500 mb out of the west) so there's not only strong wind shear but speed shear as well however there is 2 ingredients that are missing- one of them is instability and the other is surface moisture. However there is a narrow area that I would point out of a threat of an isolated severe storm and that is southern Louisiana and southern Mississippi where surface dewpoints are in the low 60s will reside. The thing that impresses me most about this is a rather potent storm system that's going to also be moving threw the region and also will be rapidly intensifying as it moves threw threw the region. Initially there will be strong pressure falls but there will also be strong pressure rises in the plains and that's going to make for a howling wind starting later today in the plains but moving threw the region tonight into tomorrow. Sustained northwest winds of 15-25 mph with much higher gusts to 40 will usher in much colder air- wind advisories seem likely. Tomorrows lows will likely reach the mid teens however with the strong northwest winds wind chill readings will feal more like the single digits and wind chill advisories look likely also. Now highs will be difficult to forecast as theres still strong cold air advection so don't look for highs reach above 35 and then Monday mornings lows will be colder then Sunday's but there's a gradual warming trend that will be started from a return flow and there could be some fun and games Wednesday night into Thursday morning. As far as a Christmas forecast is concerned- while there may not be a blizzard like last year- there certainly could be quite some fun - Zach and I will have more on that during the next week. Also make sure to drip your faucets so they dont freeze and bundle up we don't want y'all to catch a cold!!!

Oklahoma's First Snow Event Of The Season!

2010-12-07T17:08:00.004-06:00

As I type this snow is currently falling across north central and northwestern Oklahoma. Woodward was reporting snow covering the grass and visibilities dropping below one mile in some of the heavier bands.
A vigorous upper level shortwave will move southeast from the southern high plains and across the state this evening and tonight. Strong lift was generating widespread precipitation as indicated on radar. However the lower levels of the atmosphere are very dry and much of the precipitation is not reaching the ground except for in northwest and parts of north central Oklahoma where persistent falling precipitation has moistened the atmosphere enough to allow precipitation to reach the surface. While the dry air will act to limit precipitation amounts it will also provoke evaporational cooling bringing the freezing level to the surface. The wet bulb temperatures are displayed above. It's easy to point out where snow is falling as indicated by wet bulb temperatures around freezing in northwest Oklahoma.

Any snow accumulations will be confined to the grassy surfaces and I do not anticipate travel problems though in some of the convective bands closest to the surface low(which is currently over northwest Oklahoma) visibilities could be reduced significantly at times. The snow may reach central and eastern sections of the state later this evening.

Accumulating Snow Possible On Tuesday...

2010-12-04T11:14:00.005-06:00

For about the past two weeks we've been contemplating the potential for the area's first snow event of the season. I don't anticipate a winter storm by any means(at least not any more I don't) but there has been an increasing concern amongst this morning's model trends for accumulating snowfall across a good part of Oklahoma on Tuesday.
Both the NAM and GFS have a more robust shortwave in their 06z and 12z runs with more amplitude and more QPF being generated for the area. The only difference is in terms of storm track with the NAM being farthest south and the GFS farthest north. Yesterday the NAM had no shortwave and no snow and the GFS had a shortwave but little if any accumulation. The air mass will be very dry ahead of this system which will limit precipitation amounts but enhance the snow potential given evaporational cooling. Any snow looks to be light and accumulations probably less than an inch in any given location. However some of the raw model data(in particular the GFS) is suggesting a narrow swath of 1-3" snow accumulations near the I-44 corridor.

In any case this event will be relatively trivial to travel and I do not expect significant accumulations at this time.

For the weekend, expect colder conditions behind a cold front which came through early this morning. A northwesterly flow developing aloft will sustain cold temperatures(especially overnight with the dry air mass in place) through the middle part of next week.

Models Don't Have A Clue!

2010-11-30T20:49:00.004-06:00

The models continue to be variant in their solutions for next week regarding both a southern branch system and impending frontal intrusion. The ECMWF in previous runs had an anomalously large closed low intruding the area and was more aggressive in the arrival of polar air. The GFS has no such low but more of a low amplitude trough and more temperate air mass. The latest run of the ECMWF has trended towards the 06z GFS but I don't believe the GFS has a good handle on the northern stream trough being in its usual error mode. The GFS ensembles were more realistic and more of a compromise between the more amplified Euro and less than enthusiastic GFS.

The state of the teleconnections dictate that the pattern is becoming more favorable for sustained cold(at least for now) and the development of a southern branch system is becoming more likely as the trough sets up in the east and steers western storms more ESE but I don't believe it will be as suppressed as what the models are(were) thinking. I think we will know more in the coming days as hopefully consistency becomes established within the models.

Bottom line is that there still appears to be a decent potential of snow/ice early next week but whether or not it is a full blown storm or just a minor episode is to be determined. For now, stay tuned...

Tornadoes Possible Today along the Gulf

2010-11-29T09:26:00.000-06:00

Good morning everyone hope you all had a wonderfull gobble day we certainly did. Isentrophic lift associated with a warm front has established itself as scattered to numerous showers and elevated thunderstorms are blosseming. Today has the potential to be active but alot has to do with how much instability there is. Plus I want to take note that there are differences reguarding this event and thanksgiving. First difference is the position of the warm front is further south then thanksgiving- even so dewpoints before the warm front lifted were in the 50s and today so far they range from 68 in Hackberry, Lousiana to 43 at my weather station in Jacksonville, Arkansas. Right now my best guess is that 60 plus dewpoints are going to be established as far north as the Arkansas/ Lousiana border into central and southern Mississippi with 50-55 degree dewpoints further north. That's what brings me to the following from the spc folks.

This is the current day 1 tornado outlook- I can agree with this for the most part except remove the 5 percent tornado threat from central Arkansas, replace it with a 2 percent threat and move the 5 percent further south and east starting around Pine Bluff, Arkansas. Of particular interest is the 10 percent hatched area where there is a potential for a few strong tornadoes later tonight. Again this is all depending on how much sunshine this area receives. What's interesting to note is there is an analog case that was done on November 26th, 1988 were a similar thermodynamic/ kinematic situation arose and there was a couple strong tornadoes occurred in Mississippi. Speaking of the thermodynamic/ kinematic situation that models are suggesting up to 500 cape up to arklamiss region while further south into central and southern Louisiana between 1000-1500 cape is possible- in fact the latest mesoanalysis shows that ML capes are up to 500 j/kg in southwest Louisiana with 1000 not to far behind. As far as the kinematics are concerned they are quite impressive with 0-3 helicity values already between 400-500 m2^s2 and coupled with forecasted deep layer shear between 60-80 knots and 0-1 km shear at 40-50 knots it will create an idea situation for a few strong, long tracked tornadoes in Louisiana and Mississippi. Keep in mind though that the instability needs to be there to

Here's over what the hrrr (high resolution rapid refresh) model is forecasting by 4 pm.

Note the shows and thunderstorms that occurring over the area - there more scattard out in northern Louisiana and Mississippi- these ones have the highest potential to produce strong tornadoes. Now by 0z it instead of these more isolated supercells that the become more linear.

But there still more isolated in nature towards central Louisiana and there expected to backbuild later on with a threat for damaging winds, marginally severe hail, and tornadoes- which a few strong not out of the question as it develops into a qlcs (quasi-linear convective system). Bye tomorrow that the severe weather threat moves eastword into the Carolina's into Georgia and Alabama with a continued threat for damaging winds and few tornadoes. There continues to be a threat for fun and games the first week of December Zack and I will have more on that in the upcoming days once things become more clearer.

December 2009 vs. December 2010 = Disturbing Similarities!

2010-11-26T13:40:00.005-06:00

I hope everyone had a wonderful Thanksgiving! I spent the evening in Yukon yesterday with family for Thanksgiving dinner and then headed to the "Yukon's Christmas In The Park" lights display. It was cold no doubt about it but hey that only makes the holidays more festive right?

This morning was even colder. Overnight lows in many places dropped into the teens with low 20's in others. Oklahoma City dipped down to 20 this morning at the air port and it was a nippy 22 degrees at my place. Is it only convenient that they were playing on the radio this morning "Baby it's cold outside" by Vanessa Williams! Temps have warmed up nicely however as southwesterly winds return on the backside of the surface ridge of high pressure. It will be another cold night tonight but for Bedlam Saturday temps will be moderating even further.

Being a weather nut like me I'm already ahead of myself as far as weather is concerned. Looking ahead to next month it appears that the models too are stuffed with interesting things.

This graphic to the right isn't a model run but rather the current state of the Geopotential heights and anomalies. If one were to look at the teleconnections they would see that the NAO and AO are in the abyss. The negative NAO can be clearly seen to the right as well as the AO represented by all of the high latitude height rises over the pole(when it is positive later this winter you'll notice more height falls over the pole or lower pressures). We also have throw in the stratospheric warming that will be occurring over the next week or two which when you warm the pole you displace the cold farther south and east. The pattern here is conducive of some interesting things in the very near future and it is shocking at how similar things look to last December where we too had a negative AO/NAO with record blocking across the high latitudes. The only difference is there is no hyperactive southern stream due to El Nino last year. The negative PNA threw a monkey wrench in my predictions of large scale cold across the country this month with significant height falls in the west pumping the ridge in the east. It took much longer for the front to come southeast in the face of southwesterly flow aloft. It should be noted that this week is a great preview of the second half of winter where the La Nina will become the main driver of our winter weather. More troughing in the west and ridging in the east. The AO is projected to flip positive late next month or January due to a raging west based QBO.

The trough finally shifted east as blocking relaxed and this brought the much advertised cold finally to the south and east but all in all this November wasn't too terribly cold across the south and east. I have higher confidence that December will be much colder as the blocking shifts and negative AO/NAO wins over. When you throw in the high impact hurricane years I showed you several blogs back it matches well with the forecast.

Interestingly enough the GFS is catching on with this and since we won't have the tremendous height falls concentrated west the probability of a southern branch system is increasing for the first week of December( unlike these lake cutters we've been dealing with thus far) and with the projected cold it's only a matter of time before we see our first winter storm of the season.

What A Difference A Day Makes!

2010-11-25T07:42:00.008-06:00

Can you believe that a little over 12 hours ago we were in the 70's! Will Rogers World Airport actually set a record high yesterday of 79(the old record was 76 in 2006)! Low and behold all good things must come to an end as the hounds of Winter were unleashed across the southern plains in the form of a powerful well advertised cold front that has now brought MUCH colder weather to the area. The front currently was approaching far southeastern Oklahoma with Idabel sitting at 57 currently and Broken Bow at 69! Within an hour they'll be sitting in the 30's with the rest of us.
Last night I warned of the possibility of freezing precipitation behind the front as last night's RUC and NAM models showed moistening of the middle layers of the atmosphere and developing isentropic lift with frontogenesis aloft. This seems to have come together as widespread LIGHT precipitation has developed across the area. Along the front heavier rain and a few thunderstorms continued gradually shifting south and east with the front. A winter weather advisory has been issued for southern Oklahoma where the surface freezing wet bulb temperatures were catching up with the heavier precipitation and may allow for a transition to freezing rain/sleet in these areas. The higher precip rates may allow for some light accumulations of ice on exposed and mainly elevated surfaces. Travel problems will be minimal but stay alert of changing weather conditions.

Temperatures were hovering very close to freezing across the metro(though they did not get nearly as cold as what I was predicting last night) where light freezing rain/graupel(which are tiny frozen clumps of snowflakes) were being reported. Little accumulation is expected.

As upper trough axis shifts eastward from the plains today, the wintry precip will end and clouds will gradually thin and erode. Temperatures will not rise all that much this afternoon on the order of strong cold air advection. Gusty north and northwest winds will continue for the better part of the day before gradient relaxes this evening. Until then wind chills in the teens this morning and twenties this afternoon are expected. Tonight will be the coldest night of the season yet with most locations dipping into the teens and 20's. An area-wide hard/killing freeze is likely tonight. Happy Thanksgiving!

The Plunge Begins... Frozen Turkey!

2010-11-24T19:45:00.005-06:00

We set a record high of 79 degrees today at Will Rogers World Airport(the official Oklahoma city recording station). The old record high was 76 back in 2006. Unseasonably warm and even humid conditions continued however the hounds of winter are on their way.

The highly advertised cold front is now barreling through northwest Oklahoma as a type this with temperatures rapidly falling through the 40's and 30's amongst strong north and northwest winds gusting to 30-40mph. Wind chills were currently into the teens in the panhandle right now. Meanwhile unseasonably warm and humid weather continued south and east of the front with temperatures in the 60's and 70's.
The front will continue to push rapidly through the state with temperatures falling quickly into the 30's less then an hour or two after the frontal passage. Strong north and northwest winds gusting to around 40mph at times tonight will put wind chill values into the single digits across northwest Oklahoma and the teens elsewhere.

There are some thunderstorms out there and a severe threat that is not negligible. A slight risk of severe storms covers eastern Oklahoma for this evening and for a time tonight. All modes of severe weather are possible. A tornado watch is in effect for Craig, Delaware, Mayes, Nowata, Ottawa, and Rogers counties in far northeast Oklahoma until 10pm CST this evening.
The main story as mentioned will be the Arctic cold pouring into the southern plains. The graphic above shows tomorrow's morning low temperatures. The front will clear the state by 12z(if not sooner) tomorrow. I am increasingly concerned about the possibility of freezing precipitation behind the cold front. The RUC and NAM develop post frontal precip over much of the area with surface temperatures falling below freezing and cooling 850mb temperatures. As it currently appears, any wintry precipitation would be light with little in the way of accumulations. Regardless we will be keeping a keen eye on this tonight.

Thanksgiving day looks rather blustery and COLD with temperatures struggling to rise into the 40's in many locations. The coldest temperatures of the season thus far will occur Thursday night and Friday morning with low temperatures in the teens and 20's over the entire area. Have a blessed thanksgiving and stay warm!

Pattern of Extremes...

2010-11-23T20:20:00.004-06:00

A high amplitude and blocky weather pattern continues with weather extremities across the nation...

Harsh arctic cold on the order of blustery winds and heavy snows has been common place across the northwest U.S. and modeling has had no problem with this part of the forecast. Trying to bring this air mass farther south and east arises problems amongst modeling leading to a tricky forecast. The leading edge of initial wave of colder air has continued to waffle back and forth across the central and southern plains. This frontal boundary was currently beginning to lift back to the north once more stretching from west Texas into southeastern Oklahoma then becoming stationary across southern Arkansas and points east. This was the dividing line between chillier and drier air to the north and a mild and unseasonably humid air mass to the south. This air mass will continue to build back into the southern plains tonight and tomorrow bringing a return to above normal temperatures and humidity for at least one more day.

I mentioned before that modeling continues to struggle with front and its timing. I believe the models are too slow and do not give enough respect to air mass given the source region. In the models defense however, it will be difficult to bring a front south in the face of a strong southwesterly flow regime aloft. The negativity of the PNA has produced a large trough across the west and this will begin to shift east across the conus tomorrow which should allow the cold bottled up across the north and west to finally push south one more time and for good. Before we get to the cold and blustery weather that's in store for the big Holiday, we must first get through potential severe weather tomorrow. A day two slight risk has been issued for parts of Oklahoma into the Ozarks. Front will be approaching a readily buoyant air mass along with favorable deep layer shear and this will raise the concern for severe weather. However running parallel to the flow aloft will create strong frontal forcing leading to predominant linear mode. The main severe weather concerns in my eyes will be damaging winds given the sharp thermal gradient associated the front leading to steep low level lapse rates. Tornadoes are possible however, especially in any discrete activity and/or supercell features within evolving squall line. More on this tomorrow.

Behind the front comes MUCH COLDER weather. Winds will abruptly shift to the northwest and become gusty and temperatures will take a nose dive. Blustery and downright cold weather is expected for Turkey day with highs struggling to reach 40 in most areas. The main uncertainty with this front is not whether or not it will arrive(because it will believe me) but WHEN? There is a good possibility that this front could arrive much faster than model guidance suggests which will wreak havoc on temperature forecasts tomorrow I'm sure. I believe the front could arrive in the metro as early as 00z(6pm CST) tomorrow. Temperatures Thursday morning will start out below freezing with wind chills likely in the single digits and teens most areas and only moderating into the 30's to around 40 or so for highs. The coldest temperatures of the season are expected Friday morning with an area wide hard freeze anticipated. Oklahoma City currently has a low of 22 Friday morning(a heads up for black Friday shoppers!). Temperatures will moderate towards the weekend however I don't see the 70's of recent returning.

I was going to blog about some interesting things showing up for December however I'm honestly really tired and am having a writers block moment so I think I'll just leave it at this. I will mention with the current high latitude blocking remaining in place(for now anyways) and height rises returning to Alaska the cold will reload and do it all over again opening up December. This is also suggested by a negative NAO/AO right now. The GFS has been suggesting the development of a southern branch system the first week of December and with the dawning cold it could prove interesting for folks across the south and east. Again, more later.