View Full Version : Oklahoma Severe Weather Discussion - May 2011



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venture
05-09-2011, 01:13 PM
Venture, Does Wednesdays storms look like a mod to high end even for us here in central Oklahoma or just a few scattered storms popping up here and there? Whats the timeline for the Metro to see storms roll through on Wednesday? Thanks for all you do !!

If we go by the favored models of HPC this morning, Canadian and European, it would place the higher risk in most of Central and a bit of Eastern OK. It appears far western OK will have the dryline pass early but most areas east of US 183 would be in the higher risk (not "High Risk"). Time line is too early to narrow down right now until we get into either later tomorrow or early Wednesday.


Venture,,,,,What are the chances of long tracked large and damaging Tornados on Wednesday?

Thanks

Way too early to say now. The models that we have the most access to, GFS and NAM, have pulled instability figures way down this morning but I'm not buying into those runs. Will there be tornadoes? Yes. They typically cause damage when on the ground...but whether or not they will be long track or strong, it is too early to say right now since the models aren't all lined up.

Jesseda
05-09-2011, 01:20 PM
is there any activity forming for today yet? it is clear at the airport not really a cloud yet

venture
05-09-2011, 01:37 PM
is there any activity forming for today yet? it is clear at the airport not really a cloud yet

Short term model guidance does suggest we could see additional storms form much like yesterday. Generally south of I-40 in Southwest or South Central OK. The risk though is much lower today. On radar, it does appear we have some light precip trying to form just across the Red River in Western North Texas.

http://www.storm-scope.com/radar/ktlx_br1.png

jn1780
05-09-2011, 01:49 PM
Here's a conversion chart of how the NWS classifies risk areas for anyone curious.

http://www.spc.noaa.gov/misc/prob_to_cat_day1_seetext.jpg

venture
05-09-2011, 02:57 PM
Conditional severe risk extended North through SW and Central OK for today.

...SRN PLAINS...
CONDITIONAL/MRGL SVR POTENTIAL...FOR WIND/HAIL...IS EXTENDED NWD
ALONG AND JUST AHEAD OF DRYLINE AS FAR N AS PORTIONS SWRN/CENTRAL
OK. NARROW SPATIAL/TEMPORAL OPPORTUNITY EXISTS LATE THIS AFTERNOON
FOR INTENSE SFC HEATING TO OVERCOME INITIALLY STG CINH ASSOCIATED
WITH LONGSTANDING/ANTECEDENT EML FROM NW TX NWD. SOME OF THIS
ACTIVITY...WHICH WOULD BE HIGH-BASED...MAY BECOME ORGANIZED BRIEFLY
WITH POTENTIAL FOR HAIL AND STG-SVR GUSTS...GIVEN AMBIENT 35-45 KT
EFFECTIVE SHEAR AND WELL-MIXED SUBCLOUD LAYER.

venture
05-09-2011, 03:27 PM
http://www.spc.noaa.gov/products/md/mcd0704.gif

MESOSCALE DISCUSSION 0704
NWS STORM PREDICTION CENTER NORMAN OK
0423 PM CDT MON MAY 09 2011

AREAS AFFECTED...PORTIONS OF CNTRL TX INTO SWRN OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 092123Z - 092330Z

AN ISOLATED SVR STORM OR TWO COULD DEVELOP ACROSS PORTIONS OF CNTRL
TX INTO SWRN OK LATER THIS AFTERNOON. GIVEN THE ANTICIPATED SPARSE
COVERAGE OF ANY SVR STORMS...THE ISSUANCE OF A WW IS UNLIKELY.

MID-AFTERNOON SFC ANALYSIS DEPICTS A DRYLINE EXTENDING FROM 20 NNE
CSM TO THE RED RIVER 20 SSW LTS TO 45 NNW ABI AND FARTHER SSW TO 55
WSW SJT. STRONG INSOLATION OVER THE ERN PERIPHERY OF A THERMAL AXIS
/LOCATED WEST OF THE DRYLINE/ HAS RESULTED IN TEMPERATURES WARMING
INTO THE UPPER 90S TO 103 DEGREES. MODIFIED 12Z OBSERVED SOUNDINGS
AND RAPID REFRESH FORECAST SOUNDINGS SUGGEST THAT THE STRONG
DIABATIC HEATING HAS SUBSTANTIALLY REDUCED SURFACE-BASED CINH WITHIN
A NARROW CORRIDOR ALONG AND JUST EAST OF THE DRYLINE. THE REDUCTION
IN CINH...ALONG WITH LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE
DRYLINE...HAS LED TO THE INITIATION OF A FEW HIGHER-BASED CU WEST OF
THE DRYLINE. THIS INITIAL ATTEMPT AT CONVECTION MAY ALSO BE
SUPPORTED BY A SUBTLE MID-LEVEL WAVE EMERGING FROM THE HIGHER
TERRAIN OF NRN MEXICO INTO TX...ALSO RESPONSIBLE FOR HIGH-LEVEL
CLOUDINESS OVER THE MOIST SECTOR.

RECENT RUNS OF THE EXPERIMENTAL HRRR SUGGEST SOME POTENTIAL FOR ONE
OR TWO DEEPER CONVECTIVE PLUMES TO EMANATE FROM THE CU FIELD AS
HEATING CONTINUES AND THE BOUNDARY LAYER DEEPENS. ANY INCIPIENT
CONVECTION WILL BE HIGH BASED...WITH THE POTENTIAL FOR SUPERCELLULAR
STRUCTURES TO EVOLVE GIVEN EFFECTIVE BULK SHEAR MAGNITUDES OF 35-45
KT. THE THREAT FOR LARGE HAIL WILL EXIST PROVIDED VERY STEEP
MID-LEVEL LAPSE RATES /IN EXCESS OF 8.5 C PER KM/ ASSOCIATED WITH A
STRONG ELEVATED MIXED LAYER. STEEP LOW-LEVEL LAPSE RATES...IN PART
YIELDING DCAPE VALUES AOA 1300 J PER KG...SUGGESTS A POTENTIAL FOR
DMGG WINDS...AS WELL. THE THREAT FOR VERY LARGE HAIL /ALBEIT A LOW
THREAT/ MAY OCCUR IF CONVECTION CAN SUSTAIN ITSELF EAST OF THE
DRYLINE AND TRAVERSE RICHER LOW-LEVEL MOISTURE AND A VERY UNSTABLE
AIR MASS -- I.E. SFC DEWPOINTS AOA THE MIDDLE 60S SUPPORTING MLCAPE
VALUES OVER 3500 J/KG. HIGH LCL HEIGHTS AND RELATIVELY WEAK
LOW-LEVEL FLOW WILL MITIGATE THE THREAT FOR ANY TORNADOES. WITH THE
ONLY SUBSTANTIAL FORCING FOR CONVECTION EXPECTED TO BE MAINLY TIED
TO THE DRYLINE...AND GIVEN THE STRONG CINH AWAY FROM THE
DRYLINE...ANY SEVERE CONVECTIVE COVERAGE IS EXPECTED TO BE SPARSE.

..COHEN.. 05/09/2011

tornado74
05-09-2011, 03:28 PM
Way too early to say now. The models that we have the most access to, GFS and NAM, have pulled instability figures way down this morning but I'm not buying into those runs. Will there be tornadoes? Yes. They typically cause damage when on the ground...but whether or not they will be long track or strong, it is too early to say right now since the models aren't all lined up.

Thanks for posting such great information on this site. It is very helpful. I have looked at the GFS and NAM CAPE values for Day 3 and I am puzzled why the instability is so low. My meteorology skills are very basic, so forgive me if there is an obvious answer to this. The instability is already in place today, and it doesn't seem like there is anything moving through that would "strip" the atmosphere of this instability before Wednesday. So why do the models show the instability as marginal on Wednesday? Thanks in advance.

venture
05-09-2011, 03:50 PM
Norman NWS has upped the strong wording for Wednesday calling for a "Potentially Significant Severe Weather Event."

Live chat is rolling at ChatOKC.com and new blogging and resources are going at Storm-Scope.com.

http://www.srh.noaa.gov/images/rtimages/oun/fxc_Wednesday.jpg

Thunder
05-09-2011, 05:28 PM
Just caught a story on KOCO. They are attempting to induce mass panic when they displayed 3 images of recent outbreaks happening on all 3 different dates and implying that is what we will be getting on Wednesday.

venture
05-09-2011, 05:33 PM
Just caught a story on KOCO. They are attempting to induce mass panic when they displayed 3 images of recent outbreaks happening on all 3 different dates and implying that is what we will be getting on Wednesday.

I wouldn't say that, but the one thing that I did take issue with is the promoting of their Radar Predictor as a way to find out "where storms will be 2 days in advance."

redrunner
05-09-2011, 05:35 PM
Just caught a story on KOCO. They are attempting to induce mass panic when they displayed 3 images of recent outbreaks happening on all 3 different dates and implying that is what we will be getting on Wednesday.

*cough, cough*
http://www.okctalk.com/showthread.php?t=25623&p=427689#post427689
http://www.okctalk.com/showthread.php?t=25623&p=427715#post427715

venture
05-10-2011, 12:06 AM
So evening model runs look like they don't have a clue on what is going to happen Wednesday. Some quick looks appear to show several initialization errors with the data, so we'll just have to wait and see. GFS decided to hit the gas on Wednesday and move a lot of precip east, with scattered storms along the dryline. HPC guidance is recommending a blend of the UKMET/ECMWF for Wednesday. NAM is a bit too far north for their liking.

The setup looks very classic to a Great Plains Spring severe day, but instabilities all over the place. SPC outlooks are out now, and they are going Moderate for Central OK. Will post those in a second. The best line sums things up best in the evening Forecast Discussion from NWSFO Norman...


WEDNESDAY LOOKS LIKE TROUBLE. `NUFF SAID.

venture
05-10-2011, 12:12 AM
VERY strong wording here from SPC for Central OK for Wednesday...

http://www.spc.noaa.gov/products/outlook/day2probotlk_0600_any.gif

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1243 AM CDT TUE MAY 10 2011

VALID 111200Z - 121200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER A PART OF CNTRL KS AND CNTRL OK...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPR MS VLY SWD INTO CNTRL TX...

...PLAINS...
ONLY MINOR DIFFERENCES EXIST IN MODEL GUIDANCE ON THE ARRIVAL OF THE PRIMARY UPPER TROUGH INTO THE CNTRL/SRN HIGH PLAINS BY WEDNESDAY AFTN. A SUBTROPICAL IMPULSE WILL EJECT ENE AHEAD OF THE MAIN FEATURE...MIGRATING ACROSS CNTRL/NRN TX EARLY IN THE DAY. IN THE LOWER LEVELS...A LEE LOW WILL INTENSIFY OVER SWRN KS AND TRAVEL ENE INTO CNTRL KS BY WEDNESDAY NIGHT. A DRYLINE WILL MIX EWD INTO SCNTRL KS...CNTRL OK AND NCNTRL TX BY EVENING WHILE A FRONT EXISTS ENE FROM THE LOW ACROSS SRN NEB AND INTO NWRN WI.

SLY LLVL FLOW WILL MAINTAIN A MOIST BOUNDARY LAYER AIR MASS AHEAD OF THE DRYLINE WITH MLCAPE OF 2000+ EXISTING THROUGHOUT THE CNTRL/SRN PLAINS. ARRIVAL OF THE LEAD SUBTROPICAL IMPULSE WILL BE SOMEWHAT PROBLEMATIC AS STRONG PCPN SIGNAL HAS EXISTED FOR A COUPLE DAYS FROM CNTRL/NRN TX INTO ERN OK...SERN KS AND THE MO OZARKS. WHILE COVERAGE OF THIS ACTIVITY IS SOMEWHAT IN QUESTION...MODEST MID-LEVEL SWLY FLOW WILL ACCOMPANY THE SYSTEM AND BOOST VERTICAL SHEAR TO SUPPORT SUPERCELLS AND ORGANIZED LINES/CLUSTERS. LARGE HAIL APPEARS TO BE THE PRIMARY THREAT WITH THIS ACTIVITY...ALTHOUGH ISOLD TORNADOES AND DMGG WINDS WILL ALSO BE POSSIBLE.

MEANWHILE...NARROW CORRIDOR ALONG/E OF THE DRYLINE WILL PERCOLATE NW OF THE E TX/OK CLOUD SHIELD AND RESULT IN MLCAPES 2000-3000 J/KG FROM THE TX BIG COUNTRY NWD INTO CNTRL KS. AS LARGE-SCALE HEIGHT FALLS AND COOLING ASSOCD WITH THE APPROACHING TROUGH SPREAD NE...TSTMS WILL INITIATE. FIRST STORMS WILL FORM NE OF THE TRIPLE POINT/FRONT ACROSS SCNTRL NEB AND NCNTRL/NWRN KS AND THEN FARTHER SWD INTO WRN/CNTRL OK AND TX BIG COUNTRY AREA BY LATE AFTN.
INCREASING MERIDIONAL FLOW WILL RESULT IN DEEP SOUTHERLIES IN NEB/NRN KS RESULTING IN MESSY STORM MODES. STILL...BACKED NEAR SFC FLOW VCNTY THE LEE LOW WILL BE FAVORABLE FOR SUPERCELLS WITH A FEW TORNADOES AND LARGE HAIL. FARTHER S...MORE CROSS-COMPONENT DEEP LAYER SHEAR VECTORS WILL RESULT IN LONGER-LIVED DISCRETE SUPERCELLS ACROSS CNTRL/SCNTRL KS AND CNTRL OK WHERE VERY LARGE HAIL AND TORNADOES WILL BE LIKELY.

STRONGER SUPPORT FOR SUSTAINED ORGANIZED STORMS WILL CONTINUE ENE INTO ERN NEB AND IA OVERNIGHT AS SLY LLJ INTENSIFIES. STORMS WILL CONTINUE TO PRODUCE HIGH WINDS/LARGE HAIL. FARTHER S...ACTIVITY MAY NOT BE AS LONG-LIVED AS PRIMARY FORCING FOR ASCENT PASSES TO THE N AND CAP INCREASES IN THE INFLOW LAYER.

..RACY.. 05/10/2011

redrunner
05-10-2011, 12:14 AM
Fack!

jn1780
05-10-2011, 12:39 AM
Poor western OK, everyday everything is pushed a little bit further east. Not that they want to deal with severe weather, but the rain would be nice.

Thunder
05-10-2011, 04:27 AM
http://services.trb.com/kfor/fire.jpg

We're gonna have tornadoes.

tornado74
05-10-2011, 07:26 AM
Venture - are you still expecting tornadoes along the dryline tomorrow afternoon? The SPC seems to think so. However, there's a lot of chatter from other people about the low-level shear being pretty modest. How does it look to you?

BG918
05-10-2011, 07:44 AM
It will be interesting to see today's soundings. That should tell us if the atmosphere is as favorable for severe weather as it looks tomorrow.

BrettL
05-10-2011, 11:07 AM
Our thoughts on tomorrows severe weather

Hook-Echo.com Weather Blog - May 11 Severe Weather Discussion (http://hook-echo.com/2011/05/10/severe-weather-discussion-for-may-10-11-2011/)

venture
05-10-2011, 11:39 AM
Not much change with the new Day 2. Debating my own blog post/forecast before I publish it because things aren't very clear just yet. It does appear GFS is getting its act together and isn't hosing instability as much as NAM. However, there is some early convection that could be around tomorrow morning that would complicate things all the more. More thoughts in a bit.

http://www.spc.noaa.gov/products/outlook/day2probotlk_1730_any.gif

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT TUE MAY 10 2011

VALID 111200Z - 121200Z

...THERE IS A MDT RISK OF SVR TSTMS PORTIONS KS/OK...

...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE ACROSS PORTIONS
CENTRAL/SRN PLAINS FROM NEB TO S TX...

...SYNOPSIS...
MID-UPPER LEVEL SYNOPTIC PATTERN WILL BE DOMINATED BY WRN CONUS
TROUGHING...AND HIGH-AMPLITUDE RIDGING FROM CENTRAL GULF TO UPPER
GREAT LAKES. AS HEIGHTS FALL OVER PAC NW AHEAD OF CYCLONE NOW OVER
GULF OF AK...DOWNSTREAM TROUGH/RIDGE PATTERN GENERALLY WILL MOVE
SLOWLY EWD THROUGH PERIOD. LEADING WRN SHORTWAVE TROUGH -- NOW
ACCOMPANIED BY SMALL/CLOSED 500-MB CYCLONE OVER SERN MT -- IS FCST
TO EJECT SLOWLY NEWD TO SRN MB THROUGH REMAINDER DAY-1 PERIOD.
MEANWHILE...STG SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL
IMAGERY OVER LOWER CO RIVER REGION -- IS FCST TO SWIVEL NEWD ACROSS
AZ DAY-1. THIS PERTURBATION SHOULD EVOLVE INTO CLOSED 500-MB
CYCLONE OVER SAN JUAN MOUNTAINS BY 11/12Z...THEN MOVE ENEWD ACROSS
CENTRAL HIGH PLAINS BY END OF PERIOD. WEAK TROUGH OF
PAC/SUBTROPICAL ORIGIN SHOULD MOVE NEWD ACROSS CENTRAL TX EARLY IN
PERIOD...PRIOR TO 21Z.

AT SFC...CYCLONE ASSOCIATED WITH INITIAL/NRN SHORTWAVE TROUGH IS
ELONGATED ACROSS NRN SD ATTM...BUT SHOULD CONSOLIDATE THROUGH
REMAINDER DAY-1 AND MOVE NEWD ACROSS SRN MB. BY 11/12Z...EXPECT
TRAILING OCCLUDED FRONT SEWD TO TRIPLE-POINT LOW OVER MSP/LSE
REGION. DIFFUSE WARM FRONTAL ZONE -- ADJUSTED ON MESOSCALE BY
CONVECTIVE OUTFLOWS -- WILL EXTEND GENERALLY FROM TRIPLE-POINT AREA
ESEWD ACROSS OH...BENDING SWWD THEN SEWD OVER WRN/SRN APPALACHIANS
THEN SEWD ACROSS GA. WAVE LOW MAY DEVELOP ALONG WARM FRONT OVER OR
JUST OFFSHORE GA COAST EARLY IN PERIOD IF MCV DEVELOPS FROM DAY-1
CONVECTION FARTHER NW.

QUASISTATIONARY FRONT WILL EXTEND FROM NRN TRIPLE POINT SWWD ACROSS
NRN/WRN IA...SERN/S-CENTRAL NEB...TO STRENGTHENING CYCLONE OVER SWRN
KS. THIS CYCLONE SHOULD DEEPEN FURTHER AND DRIFT NEWD THROUGH
DAY...REACHING W-CENTRAL KS BY 12/00Z...WITH DRYLINE ARCHING SEWD
OVER WRN/S-CENTRAL KS...SWD ACROSS W-CENTRAL OK AND WRN PORTIONS
N-CENTRAL TX TO WRN HILL COUNTRY AND EDWARDS PLATEAU REGIONS OF TX.

...CENTRAL/SRN PLAINS...
MOST SIGNIFICANT/CONCENTRATED SVR POTENTIAL STILL APPEARS TO BE JUST
AHEAD OF DRYLINE FROM NEAR SFC LOW SEWD AND SWD OVER OK AND PORTIONS
CENTRAL TX...THOUGH SOME CAVEATS COMPLICATE POTENTIAL IN EACH OF
THREE MAIN AREAS OUTLINED BELOW. IN GENERAL...BROAD MOIST
SECTOR...CHARACTERIZED BY MID-UPPER 60S AND LOW-70S SFC DEW POINTS
AND INTENSIFYING BULK SHEAR...WILL FAVOR RATHER BROAD SVR TSTM
POTENTIAL LIKELY ASSOCIATED WITH 3 PHASES...EACH WITH SOME SPATIAL
OVERLAP...

1. EARLIEST DEVELOPMENT MAY OCCUR FROM MID-LATE MORNING THROUGH
EARLY AFTERNOON IN ASSOCIATION WITH LEADING/SRN-STREAM PERTURBATION
OVER PORTIONS CENTRAL/SRN TX...AHEAD OF DRYLINE IN ZONE OF WEAKENED
CINH. ENVIRONMENT WILL BE CHARACTERIZED BY INCREASINGLY SFC-BASED
EFFECTIVE INFLOW PARCELS AND STRENGTHENING DEEP-LAYER SHEAR CAUSED
BY EJECTING SWRN CONUS WAVE. HODOGRAPHS SHOULD BE SUFFICIENT FOR
THREAT OF SUPERCELLS AND PERHAPS TORNADOES. POSSIBLE EVOLUTION TO
MESSY CONVECTIVE MODES AND LACK OF STRONGER DIABATIC HEATING MAY BE
LIMITING FACTORS...GIVEN POTENTIAL FOR EARLY ONSET OF CONVECTION AND
SPREAD OF RELATED CLOUD COVER/PRECIP.

2. NEXT EARLIEST DEVELOPMENT IS LIKELY MIDDAY INTO MID-AFTERNOON
NEAR SFC LOW AND ADJACENT PORTIONS OF FRONT AND DRYLINE ARC OVER
KS...WHERE DEEP-LAYER FORCING WILL BE STRONGEST SOONEST WITHIN
GREAT-PLAINS CORRIDOR. RATHER LENGTHY HODOGRAPHS PROGGED IN NARROW
WARM SECTOR MAY SUPPORT SPLITTING STORMS AS WELL. SUPERCELLS WITH
LARGE HAIL...SVR GUSTS AND TORNADOES ARE POSSIBLE. CAPPING WILL BE
STRONGER FARTHER NE ALONG FRONT AND SE/S ALONG DRYLINE...BUT SVR
POTENTIAL SHOULD BRANCH OUT ALONG THOSE CORRIDORS DURING AFTERNOON.

3. AHEAD OF DRYLINE OVER PORTIONS SRN KS...OK AND N TX. DEEP-LAYER
SHEAR AND MEAN-WIND VECTORS SHOULD BE PROGRESSIVELY MORE ORTHOGONAL
TO DRYLINE WITH SWD EXTENT AND WITH TIME...CONTRIBUTING TO GREATER
POTENTIAL FOR RELATIVELY DISCRETE MODES TO LAST LONGER.
HOWEVER...PRESENCE OF CLOUD COVER FROM WARM-SECTOR CONVECTION MAY
RESULT IN NARROW OR RESTRICTED AREA OF AFTERNOON DESTABILIZATION.
SOME MASS ADJUSTMENT OF MID-UPPER LEVEL WIND FIELDS ALSO MAY
OCCUR...RELATED TO EARLIER PERTURBATION AND PRESENCE OF CONVECTION
FARTHER S...THAT COULD LEAD TO AREAS OF BACKING WITH HEIGHT
ALOFT...AND POTENTIALLY COMPLEX CONVECTIVE MODES.

jn1780
05-10-2011, 11:51 AM
Sounds like it will be this time tomorrow before we get a good idea on what will happen.

Thunder
05-10-2011, 12:14 PM
Yeah, Venture, I was checking KOCO's site for news and saw a link to their "Radar Predictor" and it was showing clouds rolling through overnight into morning hours before clearing up during the day then another wave for the afternoon. Clouds better not ruin the day, cuz I want it all to be crystal clear all day until those supercells arrive.

BG918
05-10-2011, 12:21 PM
Yeah, Venture, I was checking KOCO's site for news and saw a link to their "Radar Predictor" and it was showing clouds rolling through overnight into morning hours before clearing up during the day then another wave for the afternoon. Clouds better not ruin the day, cuz I want it all to be crystal clear all day until those supercells arrive.

Wasn't there a lot of cloud cover during the May 10 outbreak last year? Seems like I remember it clearing just a couple hours before the storms fired.

venture
05-10-2011, 12:24 PM
Tomorrow is really looking like a headache right now. Tried to sum it up best here: http://www.storm-scope.com/blog/?p=37

Short term we have storms increasing in South Central and Western OK that have the potential to drop some decent hail.

http://www.spc.noaa.gov/products/md/mcd0710.gif

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0112 PM CDT TUE MAY 10 2011

AREAS AFFECTED...N-CNTRL TX INTO OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 101812Z - 102015Z

ELEVATED CONVECTION CAPABLE OF PRODUCING SMALL HAIL WILL MOVE NWD
ACROSS PORTIONS OF N-CNTRL TX INTO CNTRL OK THROUGH THIS AFTERNOON.
WHILE AN ISOLATED THREAT FOR MARGINALLY SEVERE HAIL MAY ENSUE...ANY
SEVERE THREAT IS EXPECTED TO BE MARGINAL AND ISOLATED.

THE COMBINATION OF MID/UPPER-LEVEL ASCENT ASSOCIATED WITH A
LOW-LATITUDE WAVE EMERGING FROM NRN MEXICO INTO TX HAS PROMPTED THE
RECENT INITIATION OF ELEVATED CONVECTION ACROSS PORTIONS OF N-CNTRL
TX AT THE APEX OF A SUBTROPICAL MOISTURE PLUME. SINCE STATIC
STABILITY WITHIN THE BOUNDARY LAYER CONTINUES TO BE REINFORCED BY
AMPLE MID/HIGH-LEVEL CLOUDINESS ASSOCIATED WITH THE MOISTURE
PLUME...THE CONVECTION IS LIKELY ROOTED BETWEEN 900 AND 850 MB PER
RAPID REFRESH FORECAST SOUNDINGS AND 12Z OBSERVED SOUNDINGS.
REGARDLESS...STEEP MID-LEVEL LAPSE RATES ARE EVIDENT ACROSS THE
REGION...WITH 12Z FORT WORTH AND NORMAN SOUNDINGS INDICATING
700-500-MB LAPSE RATES OF 8.9 C PER KM AND 9.2 C PER
KM...RESPECTIVELY. AS SUCH...SMALL HAIL WILL BE A THREAT WITH THIS
ACTIVITY AS IT SHIFTS NWD...WITH THE POTENTIAL FOR ADDITIONAL
ELEVATED CONVECTION TO DEVELOP FARTHER SOUTH INTO CNTRL TX CLOSER TO
A 500-MB VORT MAX. GIVEN MUCAPE VALUES IN EXCESS OF 2000 J/KG...A
SMALL THREAT FOR MARGINALLY SVR HAIL COULD DEVELOP WITH THE MORE
VIGOROUS UPDRAFTS. HOWEVER...GIVEN EFFECTIVE BULK SHEAR MAGNITUDES
AOB 30 KT...THE OVERALL STORM ORGANIZATION/DURATION MAY BE
LIMITED...REDUCING THE OVERALL SEVERE THREAT. THUS...THE ISSUANCE OF
A WW IS UNLIKELY.

..COHEN.. 05/10/2011

venture
05-10-2011, 12:26 PM
Wasn't there a lot of cloud cover during the May 10 outbreak last year? Seems like I remember it clearing just a couple hours before the storms fired.

It isn't atypical for us to have a low stratus deck on severe days. It happens when the gulf just opens up. The key is getting the sun to burn it off by late morning and early afternoon to get some heating to take place for instability to build.

venture
05-10-2011, 12:29 PM
Bulletin - immediate broadcast requested
severe thunderstorm warning
national weather service norman ok
128 pm cdt tue may 10 2011

the national weather service in norman has issued a

* severe thunderstorm warning for...
Western pontotoc county in east central oklahoma...
Northwestern johnston county in southeast oklahoma...
Northern carter county in southern oklahoma...
Eastern garvin county in southern oklahoma...
Murray county in southern oklahoma...

* until 230 pm cdt

* at 128 pm cdt...national weather service radar indicated severe
thunderstorms along a line extending from 3 miles southeast of
davis to 4 miles southwest of milo...moving north at 40 mph.

Hazards in the warning include...
Hail up to the size of quarters...
Wind gusts to 60 mph...

* locations in the warning include ada...byng...davis...dougherty...
Elmore city...fitzhugh...graham...healdton...hennepin...h ickory...
Lake of the arbuckles...mill creek...milo...paoli...pauls valley...
Pooleville...roff...scullin...springer...stratford ...sulphur...
Turner falls...vanoss...whitebead and wynnewood.

venture
05-10-2011, 12:47 PM
Just a side note, the chat room is rolling and can be access from either http://www.chatokc.com or http://www.storm-scope.com now. Have the "live" radar up and webcam operational. Should be ready for the busy day tomorrow now.

Thunder
05-10-2011, 09:28 PM
David, where are you? I have been waiting for hours on the chat. I got a question.

The wave that came through the state, was that the one meant to come thru overnight into late morning? Or are we still expecting that wave to come? Just wondering if that wave came way early than predicted, cuz I noticed the clouds was clearing up. Would be kool if we actually have clear skies from here on out toward the big bang.

venture
05-10-2011, 11:35 PM
David, where are you? I have been waiting for hours on the chat. I got a question.

The wave that came through the state, was that the one meant to come thru overnight into late morning? Or are we still expecting that wave to come? Just wondering if that wave came way early than predicted, cuz I noticed the clouds was clearing up. Would be kool if we actually have clear skies from here on out toward the big bang.

Sorry not able to be on chat this evening. Will be in there nearly all day/evening tomorrow.

We will probably still have some stratus around in the morning due to the moisture pouring in. However, current short term model runs aren't showing a mass of precip forming in Western OK like some have been predicting. Most of the activity tonight will be mainly to the east of I-35 and shouldn't be much of an issue.

Comments I posted on Storm-Scope.com earlier...

HRRR short term model has precip staying in Western OK. It is matching up pretty well to current activity. It does hint at some additional development back to the west some near the far eastern parts of the OKC Metro. Nothing major to worry about that. Main show still on tap for later today.

GFS and NAM models are pretty much in agreement with precip placement. They break out some early precip that will impact mostly Eastern OK, this activity might be severe but not the main show. Towards late afternoon, activity is expected to break out along the dryline in Western OK. These storms will likely end up being supercells and conditions are favorable for rotating storms. Large Hail and Tornadoes will be the main threat. Both models continue to dry precip out extremely fast after dark, but not sure how accurate that is at this point. NAM is also having issues with instability forecasts again, mainly due to the morning stratus deck we'll have and probably over forecasting of precip in Eastern OK. Both models do show a narrow band of high instability right ahead of the dryline into the evening hours, so we'll need to see how it plays out.

Overall, this is still something that isn't set in stone and will be very dynamic going through the day of Wednesday.

venture
05-10-2011, 11:53 PM
SPC Continues Moderate Risk...


DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT WED MAY 11 2011

VALID 111200Z - 121200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF WCNTRL KS AND WRN OK...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN PLAINS...CNTRL PLAINS AND MID-MO VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WRN SC AND ERN GA...

...SEVERE WEATHER EPISODE WILL BE LIKELY ACROSS THE SRN AND CNTRL PLAINS TODAY WITH AN ISOLATED THREAT FOR STRONG TORNADOES...

...SRN AND CNTRL PLAINS...
AN UPPER-LEVEL LOW OVER THE FOUR CORNERS REGION WILL MOVE EWD ACROSS THE SRN ROCKIES AND DECELERATE AS THE SYSTEM MOVES INTO THE CNTRL PLAINS THIS AFTERNOON. AHEAD OF THE SYSTEM...A WELL-DEVELOPED LOW-LEVEL JET WILL BE IN PLACE ACROSS THE SRN AND CNTRL PLAINS WITH AN AXIS OF MODERATE TO STRONG INSTABILITY LOCATED FROM CNTRL AND NRN TX EXTENDING NWD ACROSS OK AND KS. MODEL FORECASTS DEVELOP A CLUSTER OF STRONG THUNDERSTORMS THIS MORNING ACROSS THE TX HILL COUNTRY ASSOCIATED WITH A SUBTLE SHORTWAVE TROUGH MOVING NEWD ACROSS THE REGION. THIS ACTIVITY MAY HAVE A HAIL THREAT AS THE CONVECTION MOVES INTO THE AXIS OF THE LOW-LEVEL JET ACROSS EAST AND NORTH TX THIS AFTERNOON. FURTHER TO THE NORTH...ACROSS WCNTRL OK AND WCNTRL KS...THE AIRMASS SHOULD REMAIN UNDISTURBED THROUGH EARLY AFTERNOON AS A DRYLINE SHARPENS ACROSS WRN KS AND WRN OK. AS LOW-LEVEL CONVERGENCE INCREASES ALONG THE DRYLINE AND THE CAP WEAKENS THIS AFTERNOON...SCATTERED THUNDERSTORM INITIATION SHOULD TAKE PLACE ON THE WRN EDGE OF THE MODERATE RISK AREA. INCREASING DEEP LAYER SHEAR ASSOCIATED WITH AN APPROACHING MID-LEVEL JET AND MODERATE INSTABILITY SHOULD BE FAVORABLE FOR SUPERCELL DEVELOPMENT. AS SUPERCELLS RAPIDLY DEVELOP...A HIGHER-END SEVERE WEATHER EVENT SHOULD UNFOLD LATE THIS AFTERNOON INTO THE EVENING ACROSS THE SRN AND CNTRL PLAINS.

CONVECTIVE INITIATION SHOULD TAKE PLACE FIRST THIS AFTERNOON ACROSS NRN KS ALONG A WARM FRONT EXTENDING ENEWD FROM SFC LOW IN WRN KS.
FORECAST SOUNDINGS FROM GOODLAND KS EWD TO SALINA KS AT 21Z SHOW MLCAPE VALUES OF 1500 TO 2500 J/KG AND 0-6 KM SHEAR VALUES AROUND 40 KT. THIS COMBINED WITH COLD TEMPS ALOFT ASSOCIATED WITH THE UPPER-LEVEL LOW TO THE WEST...SHOULD PROVIDE CONDITIONS FAVORABLE FOR LARGE HAIL AS SUPERCELLS AND/OR BOWING LINE-SEGMENTS ORGANIZE DURING THE LATE AFTERNOON. FURTHER SOUTH ALONG THE DRYLINE...FORECAST SOUNDINGS AT 21Z TO 00Z SHOW MLCAPE VALUES OF 2000 TO 3000 J/KG WITH 0-6 M SHEAR VALUES AROUND 40 KT. DEEP LAYER SHEAR SHOULD INCREASE BY 00Z AS A 60 TO 70 KT MID-LEVEL JET MOVES INTO THE SRN PLAINS. THIS COMBINED WITH 700 TO 500 MB LAPSE RATES OF 8.0 TO 8.5 C/KM SHOULD BE VERY FAVORABLE FOR LARGE HAIL. A THREAT FOR 2 INCH OR GREATER HAIL SHOULD EXIST WITH THE MORE INTENSE SUPERCELLS. IN ADDITION...LOW-LEVEL SHEAR WILL ALSO INCREASE DURING THE EARLY EVENING AS A 35 TO 50 KT LOW-LEVEL JET BECOMES FOCUSED ACROSS CNTRL OK AND SRN KS. THE GREATEST THREAT FOR TORNADOES SHOULD EXIST TO THE WEST OF THE JET CENTER IN WRN OK AND WCNTRL KS AS SUPERCELLS MATURE DURING THE EARLY EVENING. AN ISOLATED THREAT FOR STRONG TORNADOES MAY EXIST WITH THE MORE DOMINANT SUPERCELLS.

THE MAIN UNCERTAINTY WITH THE FORECAST IS STORM COVERAGE. MOST OF THE MODELS KEEP CONVECTIVE COVERAGE ACROSS WRN OK AND WRN KS RELATIVELY ISOLATED. THIS IS PROBABLY DUE TO THE UPPER-LEVEL LOW WHICH IS FORECAST TO SLOW DOWN CONSIDERABLY...KEEPING MOST OF THE LARGE-SCALE ASCENT WEST OF THE DRYLINE. AT THIS POINT...THE NAM SOLUTION AT 00Z APPEARS REASONABLE SUGGESTING THE STORMS MAY TEND TO REMAIN WIDELY GAPPED. IN SPITE OF THIS...THE SYNOPTIC PATTERN WITH A STRONG LOW-LEVEL JET RESPONSE...EJECTING MID-LEVEL JET AND WELL-DEVELOPED DRYLINE SHOULD RESULT IN A HIGHER-END SEVERE THREAT.
FOR THIS REASON...WILL MAINTAIN A MODERATE RISK ACROSS WCNTRL KS AND WRN OK.

...SRN APPALACHIAN MTNS AND CAROLINAS...
NNWLY FLOW WILL BE IN PLACE AGAIN TODAY FROM THE CNTRL APPALACHIAN MTNS SWD INTO THE CAROLINAS. SFC HEATING AND SFC DEWPOINTS AROUND 70 F SHOULD RESULT IN MODERATE TO STRONG DESTABILIZATION BY THIS AFTERNOON. SCATTERED THUNDERSTORMS APPEAR LIKELY TO DEVELOP THIS AFTERNOON IN THE WRN CAROLINAS AS A SUBTLE SHORTWAVE TROUGH MOVES SSEWD ACROSS THE REGION. MLCAPE VALUES OF 2500 TO 3500 J/KG ALONG WITH 45 TO 50 KT OF DEEP LAYER SHEAR SHOULD BE SUFFICIENT FOR SUPERCELL DEVELOPMENT. ANY SUPERCELL THAT DEVELOPS SHOULD CONTAIN AN ISOLATED THREAT FOR LARGE HAIL AND WIND DAMAGE.

...MID TO UPPER MS VALLEY...
AN AXIS OF MODERATE INSTABILITY SHOULD EXIST FROM THE LOWER OH VALLEY NWD INTO THE UPPER MS VALLEY WHERE MLCAPE VALUES SHOULD BE IN THE 3000 TO 4000 J/KG RANGE BY MID-AFTERNOON. ALTHOUGH LARGE-SCALE ASCENT SHOULD REMAIN RELATIVELY WEAK...A FEW STORMS MAY INITIATE FROM SRN MN AND ERN IA EWD ACROSS WI AND NRN IL. THE STRONG INSTABILITY AND STEEP LOW-LEVEL LAPSE RATES COULD RESULT IN A MARGINAL WIND DAMAGE THREAT WITH HAIL ALSO POSSIBLE WITH THE MORE INTENSE CELLS.

..BROYLES/STOPKOTTE.. 05/11/2011

venture
05-11-2011, 12:03 AM
So some specifics. The Moderate risk is roughly between US 183 to the west and I-35 to the east and goes down to the Red River Valley. The chance for significant tornadoes would also exist in this area.

Now one thing to take away from the SPC discussion. There are still many questions with this setup. Things are not perfect and storm coverage may not be extremely high, but what storms do form should provide a higher end severe threat. If the environment was less conducive to higher end severe weather, they probably would have dropped the Moderate Risk. However, regardless of what some people are saying out on Twitter and such, based on coverage they likely won't go to a High risk for this event unless things drastically change tomorrow as things progress.

venture
05-11-2011, 12:05 AM
One more quick side note for Thursday. Slight risk is up generally just to the east of I-35 for some large hail producers and maybe a tornado or two.

SoonerDave
05-11-2011, 05:37 AM
Hey everyone....thought things might be picking up in here and over on the chatroom. Stay safe today, everyone.

tornado74
05-11-2011, 06:52 AM
Looks like the crapvection has started west of the dryline. This doesn't have me too optimistic for today.

Jesseda
05-11-2011, 07:21 AM
crapvection?

Thunder
05-11-2011, 07:31 AM
They took away the Moderate risk. :-O

NWS still maintain an enhanced risk, but the SPC took away the moderate risk.

Thunder
05-11-2011, 07:38 AM
Looks like the crapvection has started west of the dryline. This doesn't have me too optimistic for today.


crapvection?

He is talking about this...

http://climate.cod.edu/data/satellite/1km/Oklahoma/current/Oklahoma.rad.gif

I can't believe this...

Thunder
05-11-2011, 08:02 AM
Looks like the crapvection has started west of the dryline. This doesn't have me too optimistic for today.

Do you know where the dryline actually are? It would make sense if this wave was east of the dryline, as expected for morning hours, but more further to the east (toward us). Surprised me that its actually way out west. I think Venture is still sleeping. I keep refreshing the NEXRAD and the whole thing seem to be diminishing to me, which is good. There is still 6 hours until around 3pm to burn off the clouds and really heat up. Eh, oh, Venture, hurry up wake up!

You can see NWS is still maintaining such risk, even tho the computerized SPC took it away.

http://www.srh.noaa.gov/images/rtimages/oun/fxc_Hazardous_Weather_Outlook.jpg?timestamp=130511 8459

*Graphic subject to change.

And a tweet from OUN.


ounwcm:
Computer models are not doing a great job with the storms in W OK. That's making the afternoon forecast tougher. Stay tuned!

Thunder
05-11-2011, 08:05 AM
Now the NWS removed the Enhanced/Moderate Risk after I posted that. :-O

klmadison
05-11-2011, 08:36 AM
Here is Texas Tech West Texas mesonet from Lubbock on dewpointhttp://http://wedgefest.wind.ttu.edu/gem_images/L_nwslub_plot.gif

klmadison
05-11-2011, 08:38 AM
Here is dewpoint map from Texas Tech W. Texas mesonet sitehttp://http://wedgefest.wind.ttu.edu/gem_images/L_nwslub_plot.gif

Thunder
05-11-2011, 08:49 AM
Pulled from Venture's chat.


GeogKev:
the storms are currently well east of the dryline. These storms are affecting the chances for severe weather. The more rain and clouds we have the less instability in the atmosphere.

Just as I thought, east of the dryline, not west, tornado74. Now we just wait to see how fast it all burn off and clear up.

venture
05-11-2011, 08:51 AM
Just about every forecast model failed for today so far. HRRR is trying to get a handle on this short term, but has storms going up in SW/SC OK in the next 1-2 hours and moving through Central/NC OK by 4PM before moving off to the north and east.

The dryline, if there is even one out there this morning, is well west close to the TX/NM border at this point. Morning crapvection has completely hosed the setup for today. The good thing, western OK is getting some rain which they desperately need.

Thunder
05-11-2011, 09:02 AM
GeogKev:
A quote from one of my professors Dr. Howard Bluestein on May 3rd, he said " there is too much cloud cover and the risk of tornadoes is very slim. If we have a tornado this afternoon I will eat my hat." That quote just goes to show, even the experts are stumped by mother nature.

He was telling us about the day on May 3rd 1999 had rain and cloud cover during the morning hours and cleared up by 3pm. Look what happened during the rest of the day as we all know. Just saying...

He also said the dynamics are not as impressive compared to May 3rd, but looking at that quote...anything can happen.

Just saying...

silvergrove
05-11-2011, 09:04 AM
Just about every forecast model failed for today so far. HRRR is trying to get a handle on this short term, but has storms going up in SW/SC OK in the next 1-2 hours and moving through Central/NC OK by 4PM before moving off to the north and east.

The dryline, if there is even one out there this morning, is well west close to the TX/NM border at this point. Morning crapvection has completely hosed the setup for today. The good thing, western OK is getting some rain which they desperately need.

If there are storms, they might be interesting. But if we get a good dose of rain, I'm up for that.

venture
05-11-2011, 11:44 AM
http://www.spc.noaa.gov/products/md/mcd0732.gif

MESOSCALE DISCUSSION 0732
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CDT WED MAY 11 2011

AREAS AFFECTED...ERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 111733Z - 111900Z

STORMS MAY UNDERGO INTENSIFICATION AS THEY DEVELOP EWD THROUGH THE
REMAINDER OF CNTRL INTO ERN OK THIS AFTERNOON. THE INITIAL PRIMARY
THREATS WILL BE ISOLATED LARGE HAIL AND DAMAGING WIND. AREA WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

PRE-FRONTAL BAND OF STORMS DEVELOPING ALONG WARM CONVEYOR BELT AND
IN ASSOCIATION WITH LEAD IMPULSE EJECTING NNEWD THROUGH SRN/CNTRL
PLAINS WILL LIKELY PERSIST THROUGH THE AFTERNOON. STEEP LAPSE RATES
HAVE ADVECTED ABOVE RICHER LOW LEVEL MOISTURE WITH MODERATE
INSTABILITY ACROSS ERN OK. HOWEVER...WIDESPREAD STRATUS HAS LIMITED
DIABATIC WARMING AND WILL CONTINUE TO SLOW BOUNDARY LAYER
DESTABILIZATION. ACTIVITY IS SHIFTING EAST OF THE STRONGER WINDS
ALOFT AND EFFECTIVE SHEAR ASSOCIATED WITH THE PRIMARY UPPER TROUGH
FURTHER WEST. THIS SUGGESTS STORM MODE SHOULD BE MAINLY
MULTICELLULAR INTO MUCH OF THE AFTERNOON. SOME INCREASE IN VERTICAL
SHEAR MAY OCCUR LATER IN THE AFTERNOON OR EVENING AS HEIGHTS FALL IN
RESPONSE TO VORT MAX EJECTING NEWD THROUGH THE HIGH PLAINS. LIMITED
BOUNDARY LAYER RECOVERY AND MODEST VERTICAL SHEAR COULD SERVE AS
OVERALL LIMITING FACTORS FOR A MORE ROBUST SEVERE EVENT.
NEVERTHELESS A FEW STORMS MAY BECOME CAPABLE OF PRODUCING ISOLATED
DAMAGING WIND AND LARGE HAIL.

..DIAL.. 05/11/2011

PennyQuilts
05-11-2011, 11:48 AM
That last chart made me dizzy.

venture
05-11-2011, 11:49 AM
Live chat is fully staffed now for the afternoon/evening as we watch this first batch work through and look for other storms to develop behind it (already some in SW OK). Join us at either http://www.chatokc.com or http://www.storm-scope.com.

jn1780
05-11-2011, 11:50 AM
Storms appear to be doing just that, intensifying. Severe thunderstorm warnings issued now for central oklahoma.

venture
05-11-2011, 12:28 PM
http://www.spc.noaa.gov/products/watch/ww0280_radar.gif

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 280
NWS STORM PREDICTION CENTER NORMAN OK
120 PM CDT WED MAY 11 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

CENTRAL AND EASTERN OKLAHOMA
EXTREME NORTH CENTRAL TEXAS

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 120 PM UNTIL
700 PM CDT.

WIDELY SCATTERED DAMAGING WINDS
ISOLATED WIND GUSTS TO 70 MPH POSSIBLE
WIDELY SCATTERED LARGE HAIL TO 2.0 INCHES IN DIAMETER
ISOLATED TORNADOES

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 95
STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES NORTH
NORTHEAST OF BARTLESVILLE OKLAHOMA TO 45 MILES WEST SOUTHWEST OF
ARDMORE OKLAHOMA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 278...WW 279...

DISCUSSION...PRE-FRONTAL CONVECTION OVER CNTRL OK INTO N-CNTRL TX
WILL LIKELY DEVELOP EWD WITH TIME. MODERATE INSTABILITY...STEEP
LAPSE RATES AND VERTICAL SHEAR FROM 35-45 KT WILL SUPPORT POTENTIAL
FOR BOTH MULTICELL AND POSSIBLY SOME SUPERCELL STRUCTURES WITH
ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS THE MAIN THREATS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 24035.

venture
05-11-2011, 12:57 PM
http://www.spc.noaa.gov/products/md/mcd0735.gif

MESOSCALE DISCUSSION 0735
NWS STORM PREDICTION CENTER NORMAN OK
0151 PM CDT WED MAY 11 2011

AREAS AFFECTED...SERN CO...WRN KS...FAR NWRN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 111851Z - 112015Z

THE THREAT FOR SVR STORMS INCLUDING SUPERCELLS IS EXPECTED TO
DEVELOP BETWEEN 19 AND 21Z.

SFC ANALYSIS AT 18Z DEPICTS A WARM FRONT DRAPED ACROSS NWRN KS INTO
SERN CO EXTENDING TO A SFC LOW 45 S LHX. A COLD FRONT EXTENDS SOUTH
FROM THE LOW INTO THE CNTRL TX PANHANDLE. MEANWHILE...A DRYLINE
INTERSECTS THE COLD FRONT AT A TRIPLE POINT 20 E LHX EXTENDING SEWD
TO 45 ESE GUY AND FARTHER SSE ACROSS THE ERN TX PANHANDLE. THE AIR
MASS BETWEEN THE WARM FRONT AND DRYLINE CONTINUES TO RECOVER IN THE
WAKE OF MORNING CONVECTIVE ACTIVITY...AS DEBRIS CLOUDINESS IS
ERODING IN MANY AREAS YIELDING FULL INSOLATION. THIS HAS ALLOWED
TEMPERATURES TO WARM INTO THE MIDDLE/UPPER 70S IN THE WARM
SECTOR...AMIDST DEWPOINTS IN THE 50S E/NE OF THE DRYLINE. WITHIN
THIS AREA...MODEST LOW-LEVEL MOISTURE COMBINED WITH STEEP LAPSE
RATES /DUE TO THE PROXIMITY OF THE DEEP-LAYER TROUGH CENTERED OVER
THE SRN/CNTRL ROCKIES/ HAS ALLOWED SURFACE-BASED INSTABILITY TO
INCREASE TO AOA 500 J/KG. CONVECTION IS EXPECTED TO DEVELOP DURING
THE NEXT FEW HOURS OVER SWRN KS AND SERN CO AS A MID-LEVEL VORT MAX
SWINGING THROUGH THE ERN PERIPHERY OF THE AFOREMENTIONED TROUGH
IMPACTS THE AREA. EFFECTIVE BULK SHEAR MAGNITUDES AOA 50 KT WILL
YIELD A RISK FOR SUPERCELLS...WITH AN ATTENDANT THREAT FOR DMGG
WINDS AND LARGE HAIL. TORNADOES WILL BE POSSIBLE...ESPECIALLY WHERE
THE LOW-LEVEL FLOW REMAINS RELATIVELY BACKED INVOF THE WARM FRONT
AND TRIPLE POINT. THE THREAT FOR TORNADOES COULD ALSO EVOLVE BETWEEN
THE TRIPLE POINT AND SFC LOW...WHERE THE JUXTAPOSITION OF STRONG
LOW-LEVEL VORTICITY AND BUOYANCY WILL CREATE A FAVORABLE SET-UP FOR
COLD CORE TORNADOGENESIS.

..COHEN.. 05/11/2011

icecold
05-11-2011, 02:40 PM
Just saw lightning hit the Devon Tower. Crazy.

OKCMallen
05-11-2011, 02:45 PM
I think I just _heard_ that.

FritterGirl
05-11-2011, 02:51 PM
WOW! Electricity went out momentarily at 420 W. Main building. Likely from same lightning strike. Hope they pulled those guys from the cranes. I have to think they have their own crew watching weather at all times. Wonder if the stills of the lightning strike can be pulled from the livecam. Would be an awesome shot!

Also hearing reports of small, but prolific hail in Quail Springs area. Passed by quickly, though.

Easy180
05-11-2011, 02:52 PM
Hey guys stuck at work. Is this line it or do we expect another line to form this evening?

venture
05-11-2011, 02:54 PM
Hey guys stuck at work. Is this line it or do we expect another line to form this evening?

Short term models say this is it. We are going to have a decent cold pool develop being this complex that should stabilize the atmosphere across most of the state.

jn1780
05-11-2011, 03:12 PM
Seems like a pretty positive day weather wise. Last night we were expecting isolated severe thunderstorms capable of producing large hail and tornadoes. Today we received widespread rain.

PennyQuilts
05-11-2011, 03:16 PM
Just saw lightning hit the Devon Tower. Crazy.
Is that what it hit? I saw the bolt in that direction.

PennyQuilts
05-11-2011, 03:19 PM
Out west of the airport we got over an inch in less than a half hour. Lots of thunder and lightning but not too much wind. The rain is still coming down but not nearly at the rate it was between 3:00 and 3:30. We have missed nearly every single possibility of rain for months and this is soooooo appreciated.

Uncle Slayton
05-11-2011, 03:37 PM
this is soooooo appreciated.

I'll get flamed for this, but I don't care...this is as exciting as getting clothes for Christmas.

What dark gods must I appease for tornadoes to return to central OK?