View Full Version : Severe Weather - Friday May 8th



venture
05-07-2009, 06:21 AM
Moderate Risk has been posted for the area on Friday.

http://www.spc.noaa.gov/products/outlook/day2otlk_0600.gif

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

DAY 2 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0124 AM CDT THU MAY 07 2009

VALID 081200Z - 091200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN HALF OF
OK...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID SOUTH WWD THROUGH
THE SRN PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID ATLANTIC
STATES...

CORRECTED FOR GENERAL TSTM LINE ACROSS GULF COAST STATES AND 5%
SEVERE PROBABILITY LINE IN NW TX

...SYNOPSIS...
MODELS REMAIN IN GOOD AGREEMENT WITH THE EVOLUTION OF THE MID/UPPER
FLOW PATTERN THROUGH DAY 2 /FRI/...AS A POSITIVELY TILTED TROUGH
OVER THE NRN HIGH PLAINS AT START OF PERIOD BECOMES ORIENTED
NEUTRALLY AS IT REACHES THE UPPER MS VALLEY. H5 HEIGHT FALLS WILL
SPREAD EWD INTO NORTH CENTRAL U.S./CENTRAL PLAINS AIDING IN
TIGHTENING THE MID LEVEL HEIGHT GRADIENT...AS A STRONG ELONGATED
RIDGE STRETCHES FROM MEXICO/TX TO FL. THIS WILL RESULT IN WNWLY
FLOW ALOFT BECOMING MORE ZONAL AND SHIFTING SWD TOWARD THE SRN
PLAINS AND OZARKS/MID SOUTH. MEANWHILE...A SHORTWAVE TROUGH LOCATED
OVER NWRN ONTARIO/UPPER GREAT LAKES REGION AT 12Z FRIDAY WILL TRACK
EWD ACROSS ONTARIO. A LEAD IMPULSE SHOULD MOVE OFF THE NRN AND MID
ATLANTIC COAST EARLY DAY 2...WHILE A WEAKER IMPULSE TRACKS EWD FROM
THE OH VALLEY REACHING THE MID ATLANTIC STATES FRIDAY AFTERNOON.

AT THE SURFACE ACROSS THE CENTRAL STATES...AN OUTFLOW BOUNDARY ALONG
SRN PERIPHERY OF LATE DAY 1 MCS EXPECTED BE ONGOING AT 12Z FRIDAY
ACROSS THE NRN HALF OF OK/SRN KS INTO OZARKS SHOULD EXTEND WWD FROM
CENTRAL AR THROUGH CENTRAL OK TO THE TX PANHANDLE.
ANOTHER...GENERALLY E-W BOUNDARY IS EXPECTED TO EXTEND FROM KS EWD
THROUGH LOWER MO TO OH VALLEYS. MEANWHILE...FARTHER N...A COLD
FRONT ATTENDANT TO THE UPPER TROUGH GREAT LAKES TROUGH AND AHEAD OF
NRN HIGH PLAINS TROUGH WILL SPREAD E/SEWD INTO UPPER MS VALLEY AND
CENTRAL PLAINS BY LATE FRIDAY AFTERNOON.

...SRN PLAINS...
AN MCS IS EXPECTED TO BE ONGOING AT 12Z FRIDAY OVER NRN OK/SRN KS
INTO THE OZARKS. SWLY LLJ WILL TRANSLATE EWD ACROSS AR/MID SOUTH
WITH WAA AND DESTABILIZATION DOWNSTREAM OF THIS COMPLEX LIKELY
MAINTAINING THIS SYSTEM AS IT PROGRESSES EWD FRIDAY MORNING/
AFTERNOON. INCREASING EFFECTIVE BULK SHEAR INTO THE MID SOUTH
SHOULD SUPPORT AN ORGANIZED SEVERE WEATHER THREAT WITH THIS
ACTIVITY.

MEANWHILE...STRONG SURFACE HEATING IS EXPECTED TO DEVELOP ACROSS
MUCH OF THE SRN HALF OF OK AND WWD THROUGH TX PANHANDLE TO SERN
CO/SWRN KS ALONG AND S OF MORNING MCS. STRENGTHENING SLY LLJ INTO
SRN OK DURING THE LATE AFTERNOON WILL INCREASE CONVERGENCE ALONG THE
E-W OUTFLOW BOUNDARY. THIS COMBINED WITH FORCING FOR ASCENT WITHIN
ENTRANCE REGION OF A MID LEVEL JET EXPECTED OVER THE OZARKS FRIDAY
AFTERNOON WILL SUPPORT TSTM DEVELOPMENT ACROSS MUCH OF CENTRAL/ERN
OK. VERY STEEP LAPSE RATES /EXCEEDING 8 C/KM/...SURFACE HEATING AND
RICH MOISTURE /SURFACE DEWPOINTS IN THE LOWER 70S/ WILL SUPPORT A
VERY UNSTABLE AIR MASS WITH MLCAPE EXCEEDING 3000 J/KG ACROSS
CENTRAL OK. INCREASING WLY MID LEVEL WINDS ACROSS THIS REGION BY
PEAK HEATING WILL STRENGTHEN DEEP LAYER SHEAR FOR SUPERCELLS...WITH
AN ATTENDANT THREAT FOR TORNADOES...VERY LARGE HAIL AND DAMAGING
WINDS. GIVEN THE LIKELIHOOD FOR TSTM DEVELOPMENT WITHIN THIS VERY
UNSTABLE/ STRONGLY SHEAR ENVIRONMENT...PARTS OF CENTRAL/ERN OK HAVE
BEEN UPGRADED TO A MODERATE RISK. ANOTHER MCS WITH ATTENDANT SEVERE
THREAT IS EXPECTED TO DEVELOP ACROSS MAINLY OK AND SPREAD EWD INTO
AR FRIDAY NIGHT AS LOW LEVEL WAA INCREASES ALONG THE NOSE OF A
STRONG VEERING LLJ.

FARTHER WNW...LOW LEVEL UPSLOPE FLOW INTO SERN CO SHOULD AID IN TSTM
DEVELOPMENT FRIDAY AFTERNOON. ORGANIZED SEVERE STORMS WILL BE
POSSIBLE AS ACTIVITY MOVES OFF THE HIGHER TERRAIN TOWARD SWRN KS/OK
PANHANDLE AND FAR NERN NM...WHERE THE AIR MASS WILL BE MODERATELY
UNSTABLE AND STRONGLY SHEARED.

Luke
05-07-2009, 06:28 AM
We're hoping for nice weather for our Wichita Mountain trip tomorrow. See what you can do about that. ;)

Thunder
05-07-2009, 06:36 AM
Isn't that nice, how the risk is specific to the main body of the state.

venture
05-07-2009, 07:49 AM
Pretty much the gist of thins for Friday will be dependent on the MCS/MCC that develops tonight. The best conditions for development will be south of where the complex tracks tonight/friday morning. If it sweeps through most of the Metro, the threat will be farther south. It also comes down to where the outflow boundary sets up.

Latest NAM that ran earlier this morning has the complex staying in KS/Far NE OK/NW AR. It does show development across the area on Friday afternoon. I don't like using GFS for short term forecasts, but it echoes NAM. It does go a bit faster with the outflow boundary pushing well south of I-40 by 7PM...which may push the most severe activity farther south. if the complex goes more north, I don't see the boundary moving that fast to the south.

Karried
05-07-2009, 08:50 AM
Great - outdoor concert at the Zoo Amphitheater tomorrow night. I'm not going but the kids are.

I doubt they allow umbrellas. Does the concert proceed rain or shine?

What do they do if a tornado hits? Any safe areas?


This weather is ruining my life.

westsidesooner
05-07-2009, 09:22 AM
If I remember correctly Karried the Zoo has a "The show goes on" rain or shine policy. And I doubt umbrellas are allowed. Good question on shelter at the zoo, I think the OEM bunker is right next door though.

As for tomorrow I still think the outflow boundary from any overnight MCS may push further south than anticipated.....its been happening all spring. I noticed on the models that they have an intersting dryline bulge tomorrow afternoon over NW Texas/SW Oklahoma depending on which model you look at. That could mean that south central Oklahoma may get the worst of it tomorrow. Maybe Pauls Vally to Ardmore area.

The weather has been tough for me this spring too, I do alot of landscaping and currently have several projects ongoing at home......I tried to squeeze in some last night and got my first mosquito attack.....I hate mosquitos. And today....should be a sauna if the sun comes out. I should smell pretty by this evening. :ohno:

venture
05-07-2009, 01:00 PM
MOD Risk dropped for now.

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CDT THU MAY 07 2009

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM OK AND VICINITY EWD INTO
THE MID MS/TN VALLEYS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN PORTIONS OF NC/SERN
VA...

...SYNOPSIS...
BROAD CYCLONIC FLOW AT MID-LEVELS WILL PREVAIL ACROSS THE CONUS THIS
PERIOD...WITH SEVERAL SMALLER-SCALE FEATURES MOVING THROUGH THE
FAST/GENERALLY WLY FLOW. THE STRONGEST FEATURE -- MOVING ACROSS THE
N CENTRAL CONUS -- WILL DRIVE CYCLOGENESIS OVER THE UPPER MIDWEST.
ELSEWHERE...A SURFACE LOW WILL LINGER OVER TX...WITH A BAROCLINIC
ZONE EXTENDING NEWD TOWARD THE MID MS VALLEY REGION THROUGH THE
PERIOD.

...OK AND VICINITY EWD INTO THE MID MS/TN VALLEY REGION...
ONE OR MORE MCS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD
ACROSS PARTS OF KS/OK AND THE OZARKS -- WHICH SHOULD PERSIST/SHIFT
EWD THROUGH THE DAY IN CONJUNCTION WITH THE VEERING/EWD-MOVING
LOW-LEVEL JET. WITH SOME DESTABILIZATION OF THE MOIST LOW-LEVEL
AIRMASS THROUGH THE DAY AND WITH FAVORABLE SHEAR ACROSS THIS
REGION...THREAT FOR HAIL AND/OR LOCALLY-DAMAGING WINDS WILL LIKELY
ACCOMPANY BOTH THE ONGOING STORMS AND ANY CONVECTIVE REDEVELOPMENT
NEAR ASSOCIATED CONVECTIVE BOUNDARIES.

FARTHER W DURING THE AFTERNOON...DAYTIME HEATING OF THE MOIST
BOUNDARY LAYER BENEATH A PLUME OF VERY STEEP MID-LEVEL LAPSE RATES
WILL RESULT IN VERY STRONG DESTABILIZATION FROM ERN OK SWD INTO NERN
TX...NEAR AND S OF A WARM FRONT EXTENDING FROM A NW TX SURFACE LOW
ENEWD ACROSS OK. ISOLATED STORMS MAY DEVELOP WITHIN THE WARM SECTOR
DURING THE AFTERNOON -- BOTH NEAR THE WARM FRONT AND POSSIBLY INVOF
LEFT-OVER CONVECTIVE BOUNDARIES. HOWEVER...THE LACK OF AN
APPRECIABLE FEATURE ALOFT SUGGESTS THAT CAPPING SHOULD GENERALLY
HINDER CONVECTIVE DEVELOPMENT -- ESPECIALLY S OF THE RED RIVER.
WITH MODERATE/VEERING FLOW ACROSS THIS REGION...SHEAR WILL SUPPORT
SUPERCELLS -- AIDED IN INTENSITY BY THE STRONG INSTABILITY. THUS --
VERY LARGE HAIL WILL BE POSSIBLE WITH ANY STORM WHICH CAN DEVELOP
DURING THE AFTERNOON...ALONG WITH LOCALLY-DAMAGING WINDS.

OVERNIGHT...AN INTENSIFYING LOW-LEVEL JET AND RESULTING INCREASE IN
WARM ADVECTION WILL FUEL MUCH MORE WIDESPREAD -- BUT LIKELY SLIGHTLY
ELEVATED -- STORM DEVELOPMENT ACROSS OK. DEGREE OF INSTABILITY AND
AMPLE SHEAR WILL SUPPORT A CONTINUED SEVERE THREAT THROUGH THE
EVENING AND INTO THE OVERNIGHT HOURS...WITH LARGE HAIL AND DAMAGING
WINDS REMAINING THE PRIMARY SEVERE THREATS. WITH MAIN SEVERE
POTENTIAL LIKELY TO BE SLIGHTLY-ELEVATED AND AFTER DARK...IT APPEARS
THAT SEVERE POTENTIAL WILL REMAIN BELOW MODERATE RISK THRESHOLDS.

venture
05-07-2009, 11:20 PM
Moving things over to this thread. A *EXTREMELY* rare PDS Severe Thunderstorm watch which now includes the northern counties in OK.

http://www.spc.noaa.gov/products/watch/ww0264_radar.gif

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 264
NWS STORM PREDICTION CENTER NORMAN OK
1205 AM CDT FRI MAY 8 2009

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

A LARGE PART OF KANSAS
NORTHERN OKLAHOMA

EFFECTIVE THIS FRIDAY MORNING FROM 1205 AM UNTIL 800 AM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

EXTREMELY DAMAGING THUNDERSTORM WIND GUSTS TO 80 MPH...LARGE HAIL
TO 3 INCHES IN DIAMETER...AND DANGEROUS LIGHTNING ARE POSSIBLE IN
THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES WEST OF
GARDEN CITY KANSAS TO 25 MILES EAST SOUTHEAST OF CHANUTE KANSAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU4).

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 260...WW 261...WW
262...WW 263...

DISCUSSION...TSTMS/SUPERCELLS EXPECTED TO FORM IN THE NEXT 1-2 HOURS
IN WAA AREA ALONG SRN FRINGE OF UPR DISTURBANCE AMPLIFYING ESE
ACROSS THE CNTRL HI PLNS. COMBINATION OF INCREASINGLY RICH MOIST
INFLOW...DEEP EML...AND SEASONABLY STRONG/LARGELY UNIDIRECTIONAL WLY
MID/UPR LVL FLOW SHOULD SUPPORT RAPID STORM INTENSIFICATION ONCE
CELLS FORM. ALTHOUGH A RISK FOR ISOLD TORNADOES WILL EXIST DURING
EARLY STAGES OF STORM DEVELOPMENT...SFC-BASED CIN AND LIKELIHOOD FOR
NUMEROUS STORM INTERACTIONS ONCE ACTIVITY DEVELOPS SUGGEST THAT MAIN
SVR THREAT EARLY-ON WILL BE VERY LARGE HAIL. SIZABLE DCAPE SHOULD
FOSTER SUBSEQUENT EVOLUTION INTO A FORWARD-PROPGATING MCS...WITH
FAIRLY WIDESPREAD DMGG WIND/HAIL.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 29035.

SEVERE THUNDERSTORM WATCH PROBABILITIES FOR WS 0264 NWS STORM PREDICTION CENTER NORMAN OK
1211 AM CDT FRI MAY 08 2009

WS 0264 PDS
PROBABILITY TABLE:
PROB OF 2 OR MORE TORNADOES : 20%
PROB OF 1 OR MORE STRONG /F2-F5/ TORNADOES : 10%
PROB OF 10 OR MORE SEVERE WIND EVENTS : >95%
PROB OF 1 OR MORE WIND EVENTS >= 65 KNOTS : 70%
PROB OF 10 OR MORE SEVERE HAIL EVENTS : >95%
PROB OF 1 OR MORE HAIL EVENTS >= 2 INCHES : 50%
PROB OF 6 OR MORE COMBINED SEVERE HAIL/WIND EVENTS : >95%

&&
ATTRIBUTE TABLE:
MAX HAIL /INCHES/ : 3.0
MAX WIND GUSTS SURFACE /KNOTS/ : 70
MAX TOPS /X 100 FEET/ : 550
MEAN STORM MOTION VECTOR /DEGREES AND KNOTS/ : 29035
PARTICULARLY DANGEROUS SITUATION : YES

Thunder
05-07-2009, 11:30 PM
Venture, somehow I don't feel excited. lol

venture
05-08-2009, 08:25 AM
Personally think the risk to the Metro is limited today unless a storm can bust through the cap early before the front passes. Otherwise, probably just scattered rain and storms with some hail around for us. The monster hail storms should be south and east, with the highest tornado threat also south along the red river and to the east. Outflow from Derecho is moving through Metro right now and should be a focus for development later. The front is behind the outflow boundary and once that passes, we may see some storms/rain but nothing on the high end severe wise.

http://www.spc.noaa.gov/products/activity_loop.gif

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0709 AM CDT FRI MAY 08 2009

VALID 081300Z - 091200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS MORNING OVER PORTIONS OF
SOUTHERN MO AND NORTHERN AR...

...THERE IS A SLGT RISK OF SVR TSTMS FROM EAST TX INTO THE OH
VALLEY...

...DERECHO IN PROGRESS THIS MORNING OVER SOUTHERN MO/NORTHERN AR...


...TX/OK/AR/LA THIS AFTERNOON...
STRONG DAYTIME HEATING AND AMPLE MOISTURE ARE FORECAST THIS
AFTERNOON ALONG AND EAST OF SURFACE BOUNDARY EXTENDING FROM EASTERN
OK INTO NORTH TX. MLCAPE VALUES OF 3000-4000 J/KG ARE POSSIBLE
ALONG THIS AXIS...BUT A RATHER STRONG CAPPING INVERSION WILL LIKELY
PERSIST. A COMBINATION OF DIURNAL HEATING AND CONVERGENCE ALONG THE
BOUNDARY ARE EXPECTED TO LEAD TO AT LEAST ISOLATED SEVERE STORMS
FROM WEST OF DFW TO FSM THIS AFTERNOON AND EVENING. EFFECTIVE SHEAR
PROFILES SUGGEST THAT SUPERCELL STRUCTURES ARE LIKELY...ESPECIALLY
OVER OK PORTION OF AREA. VERY LARGE HAIL AND DAMAGING WINDS WILL BE
POSSIBLE WITH STRONGER CELLS.

Thunder
05-08-2009, 08:36 AM
Another ruined day! http://l.yimg.com/us.yimg.com/i/mesg/emoticons7/14.gif

westsidesooner
05-08-2009, 09:17 AM
As for tomorrow I still think the outflow boundary from any overnight MCS may push further south than anticipated That could mean that south central Oklahoma may get the worst of it tomorrow. Maybe Pauls Vally to Ardmore area.

90% of the time this spring I have been wrong in my predictions as to what will happen with regards to severe weather. I wish this had been one of those times...Last night I watched the storms fire up in NW Kansas after midnight, finally went to bed around 130 only to get up again at 6 to check their progress. I watched the live feed on the Springfield Mo. website as the drecheo moved through this morning. It was very impressive on radar....esp velocity mode. The wrap around on the back side of this complex near the coma was/is amazing. Widespread severe damage all the way from Wichita Kansas into southern Missouri. Reports of two tornadoes in the Springfield area, and many homes badly damaged from straight line winds all across the region. Estimates of up to 80-100moh winds widespread. Now heading quickly towards Memphis and the boothill of MO.

On the bright side, this was a very strong complex and maybe its better that it did miss us. I like my roof and electricity. And Karrieds' kiddos should be fine tonight!!! My thoughts go out to all those effected. But I was hoping for a nice shelf cloud this morning...maybe sunlit, like I said my cameras getting dusty. The photographer in me is having SDS.

The OFB looks to be passing Norman ATTM. So any severe weather will be south and east.....unless Im wrong again. So with me saying that we should all look out. lol

Charlie40
05-08-2009, 09:37 AM
I think we have pretty much missed any action here in OKC metro will be south of us as usual..

venture
05-08-2009, 10:46 AM
Like stated earlier, pretty much all short term model guidance shows precip staying south and east of I-44.

new DY1 Outlook pulls all of the Metro out of the risk area. Enjoy a dry evening...hopefully.

westsidesooner
05-08-2009, 11:26 AM
Wish I could drive down to Mccalester today!!! Oh Yeah and this is the anniversary of the May 8th and 9th tornadoes. That was a scary two days.

Just wanted to add this. Damage reports in Kansas and Missouri are coming in. Theres ALOT of damage. Looks like the schools took it on the chin. I'm sure we'll be seeing footage on the news this evening. Heres a partial list I found. Damage reports | KY3 | Local (http://www.ky3.com/news/local/44588752.html)

Overall a very impressive/damaging event for those north and northeast of us. Almost another landocane (just what I call em) I might try to post a few questions/observations on anvilcrawlers this afternoon about this event.

OKCisOK4me
05-08-2009, 11:39 AM
That's what I was gonna say. Ahhhhhh, another dry day..

venture
05-08-2009, 12:38 PM
Wish I could drive down to Mccalester today!!! Oh Yeah and this is the anniversary of the May 8th and 9th tornadoes. That was a scary two days.

Just wanted to add this. Damage reports in Kansas and Missouri are coming in. Theres ALOT of damage. Looks like the schools took it on the chin. I'm sure we'll be seeing footage on the news this evening. Heres a partial list I found. Damage reports | KY3 | Local (http://www.ky3.com/news/local/44588752.html)

Overall a very impressive/damaging event for those north and northeast of us. Almost another landocane (just what I call em) I might try to post a few questions/observations on anvilcrawlers this afternoon about this event.

Just about another month until our Derecho season starts here.

Will be working on Anvilcrawlers.com a bit this weekend to hopefully bring some more features and stuff online, so that way the site is actually useful. : )

Karried
05-08-2009, 01:11 PM
Yay!

Outdoor concert at the Zoo... whew! Now I won't have to worry about the family being hurt!

I hope we get very little rain.. it's going to be steamy! I'll be enjoying my nice A/C. Poor hubby!

venture
05-08-2009, 03:17 PM
http://www.spc.noaa.gov/products/md/mcd0765.gif

MESOSCALE DISCUSSION 0765
NWS STORM PREDICTION CENTER NORMAN OK
0342 PM CDT FRI MAY 08 2009

AREAS AFFECTED...SRN/ERN OK...N-CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 082042Z - 082215Z

STRONG CAPPING INVERSION SHOULD WEAKEN SUFFICIENTLY FOR TSTM
DEVELOPMENT BY EARLY EVENING ALONG AND N OF COLD FRONT/RESIDUAL
OUTFLOW BOUNDARY IN SRN/ERN OK INTO N-CNTRL TX. MAIN UNCERTAINTY
REMAINS IN TIMING OF INITIATION...WITH CONSENSUS OF GUIDANCE
SUGGESTING AROUND 22Z. GIVEN EXTREME INSTABILITY...ONCE INITIATION
APPEARS TO BE COMMENCING A WW WILL LIKELY BE ISSUED.

20Z SUBJECTIVE SURFACE ANALYSIS PLACED A LOW CENTERED 20 E
SPS...WITH A COMPOSITE COLD FRONT/OUTFLOW BOUNDARY ARCING NEWD INTO
CNTRL/ERN OK TO FSM AND AN ATTENDANT DRY LINE S/SWD TO THE EDWARDS
PLATEAU. VISIBLE SATELLITE IMAGERY DEPICTS CU GRADUALLY BUILDING
BETWEEN ABI AND MWL...WITH MORE VIGOROUS CU DEVELOPMENT BETWEEN OKC
AND MKO. STRONG CAPPING INVERSION REMAINS NOTED ON RECENT ACARS DATA
INVOF OKC/DAL. HOWEVER...MODIFIED FORECAST SOUNDINGS/RAOBS SUGGEST
MLCIN SHOULD BE MINIMAL ACROSS N-CNTRL TX WHERE SURFACE TEMPERATURES
HAVE REACHED 95 TO 100 DEG F WITH DEW POINTS FROM 65 TO 70 DEG F.
CONTINUED HEATING AND CONVERGENCE ASSOCIATED WITH THE SWD-SAGGING
BOUNDARY SHOULD BE SUFFICIENT FOR TSTM INITIATION AROUND 22Z. AN
EXTREMELY UNSTABLE AIRMASS AMIDST MODERATE DEEP-LAYER SHEAR WOULD
SUPPORT RAPID DEVELOPMENT OF SUPERCELLS WITH VERY LARGE HAIL.
UPSCALE GROWTH SHOULD LEAD TO CLUSTERS/QUASI-LINEAR SEGMENTS WITH
EMBEDDED SUPERCELL STRUCTURES PRODUCING LARGE HAIL/DAMAGING WINDS
AND ISOLATED TORNADOES.

westsidesooner
05-08-2009, 03:34 PM
I was wondering how long it would take the SPC to mention that area. Cells now forming near Okemah, and from Abilene to just se of Wichita falls. These could go up really quick. More should form across south central Oklahoma. I'm sure a watch will be issued shortly. Still wish I could have gone to McAlester today. DFW is looking promising too.