SPC AC 250102
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0802 PM CDT SAT MAY 24 2008
VALID 250100Z - 251200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE PLAINS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE ERN FL PENINSULA...
...W/NW TX INTO OK/PARTS OF SRN KS...
LATEST MODELS SUGGEST DRY LINE WILL CONTINUE TO RETREAT WNWWD
THROUGH W TX AND WRN OK INTO THE TX PANHANDLE AS SELY NOCTURNAL LOW
LEVEL JET STRENGTHENS TO 40-50 KT THIS EVENING. THIS JET IS
EXPECTED TO VEER TO SLY OVERNIGHT. STEEP MID LEVEL LAPSE RATES /UP
TO 8 C/KM/ AND MODERATE INSTABILITY SUPPORT A POTENTIAL FOR
HAIL...SOME VERY LARGE...IN ADDITION TO STRONG WIND GUSTS ACROSS W
TX INTO OK. WAA/ASCENT ALONG AXIS/NOSE OF THIS JET AND UPPER LEVEL
DIFFLUENT FLOW REGIME DEVELOPING TONIGHT ACROSS W TX/SWRN OK...AS
SRN STREAM H25 JET MOVES ACROSS NRN MEXICO INTO SW TX SHOULD SUPPORT
ADDITIONAL TSTM DEVELOPMENT THROUGH TONIGHT ALONG RETREATING DRY
LINE.
FARTHER N INTO NRN OK/SRN-SERN KS...ONGOING LONG-LIVED TORNADIC
SUPERCELL IS EXPECTED TO PERSIST AND LIKELY GROW UPSCALE INTO A
MESOSCALE CONVECTIVE COMPLEX SUPPORTED WITH ASCENT FROM THE
STRENGTHENING LLJ ADVECTING A VERY MOIST AND STRONGLY UNSTABLE AIR
MASS INTO THIS REGION. EFFECTIVE BULK SHEAR VALUES AROUND 50 KT
WILL MAINTAIN ORGANIZED STORM STRUCTURE WITH AN ATTENDANT THREAT FOR
TORNADOES THROUGH THE EVENING...IN ADDITION TO HAIL...SOME LARGE...
AND DAMAGING WIND GUSTS. THIS ACTIVITY WILL AFFECT MUCH OF NRN OK
AND MAY MOVE INTO ADJACENT PARTS OF SRN KS.
...CENTRAL/NRN PLAINS TO UPPER MS VALLEY...
UPPER LOW CENTERED OVER ERN MT WILL MOVE SLOWLY NWD THIS FORECAST
PERIOD...WHILE SEVERAL ATTENDANT SHORT WAVE TROUGHS EXTENDING ESEWD
ACROSS THE DAKOTAS TRANSLATE NNEWD. ASCENT WITH THESE FEATURES WILL
SUPPORT ADDITIONAL TSTM DEVELOPMENT OVERNIGHT. ONGOING STRONG TO
SEVERE TSTMS EXTENDING FROM SWRN-SERN ND INTO ERN SD ARE EXPECTED TO
PERSIST THROUGH THE EVENING WITHIN NARROW MOIST/INSTABILITY AXIS
EXTENDING NWWD INTO THIS REGION. EFFECTIVE BULK SHEAR VALUES OF
35-60 KT REMAIN FAVORABLE FOR ORGANIZED STORMS PRODUCING HAIL...SOME
LARGE...AND DAMAGING WINDS/ISOLATED TORNADOES.
AS THE SHORT WAVE TROUGHS TRACK NNEWD TONIGHT...50-60 SWLY MID LEVEL
JET IS EXPECTED TO DEVELOP INTO MN...WITH SLY LLJ OVER THE CENTRAL/
NRN PLAINS VEERING TO SWLY AND EXTEND NEWD INTO IA/MN. PLUME OF LOW
LEVEL MOISTURE ALONG THIS LLJ AXIS AND ATTENDANT WAA IS EXPECTED TO
SUPPORT TSTM DEVELOPMENT OVERNIGHT FROM POTENTIALLY AS FAR S AS NWRN
MO AND NWD THROUGH IA TO MN. AIR MASS EAST OF CURRENT ACTIVITY IS
DRIER AND MORE STABLE IN THE BOUNDARY LAYER PER 00Z MPX SOUNDING.
HOWEVER...MODERATE ELEVATED INSTABILITY EXPECTED INTO THIS REGION
TONIGHT COMBINED WITH SUFFICIENT EFFECTIVE BULK SHEAR...GIVEN
STRENGTHENING MID LEVEL AND LOW LEVEL WINDS...IS EXPECTED TO SUPPORT
A THREAT FOR ELEVATED STORMS PRODUCING HAIL. ISOLATED DAMAGING
WINDS WILL ALSO BE POSSIBLE GIVEN THE DRY BOUNDARY LAYER CURRENTLY
EVIDENT ACROSS THIS REGION.
...ERN FL PENINSULA...
ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE THIS EVENING...
BUT OVERALL SEVERE WEATHER THREAT SHOULD CONTINUE TO DIMINISH. FOR
ADDITIONAL MESOSCALE DETAILS...REFER TO SPC MESOSCALE DISCUSSIONS
FOR THIS REGION.
..PETERS.. 05/25/2008
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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