SPC AC 091245
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0745 AM CDT SUN MAY 09 2010
VALID 091300Z - 101200Z
...NO SVR TSTM AREAS FORECAST...
...CENTRAL/SRN PLAINS THROUGH TONIGHT...
ONE MIDLEVEL TROUGH WILL MOVE EWD/NEWD OVER NEW ENGLAND
TODAY...WHILE AN UPSTREAM TROUGH PROGRESSES EWD FROM CENTRAL CA TO
THE FOUR CORNERS BY 10/12Z. AT THE SURFACE...A COLD FRONT IN THE
WAKE OF THE NEW ENGLAND TROUGH WILL BEGIN TO STALL ACROSS FL. THE
WRN EXTENT OF THIS BAROCLINIC ZONE WILL MOVE NWD ACROSS TX IN
RESPONSE TO LEE CYCLOGENESIS ACROSS NE CO...AND AN INDUCED SLY LLJ
ACROSS THE SRN/CENTRAL PLAINS. THE LLJ WILL DRAW RICH LOW-LEVEL
MOISTURE /BOUNDARY LAYER DEWPOINTS IN THE MID 70S/ NWD ABOVE THE
FRONTAL SURFACE AS A PLUME OF STEEP MIDLEVEL LAPSE RATES SPREADS EWD
FROM THE HIGH PLAINS. THESE PROCESSES WILL SUPPORT A CONTINUATION
OF ELEVATED THUNDERSTORM POTENTIAL THROUGH THE PERIOD ACROSS N
TX/OK/AR...WITH A GRADUAL NWD EXPANSION OF THE CONVECTION OVERNIGHT
AS THE LLJ STRENGTHENS.
THE STEEP MIDLEVEL LAPSE RATES AND INCREASING LOW-LEVEL MOISTURE
WILL RESULT IN THE DEVELOPMENT OF MODERATE INSTABILITY /MUCAPE OF
1500-2000 J PER KG...ROOTED IN THE 850-700 MB LAYER/ OVERNIGHT FROM
NW TX OVER WRN/CENTRAL OK INTO SRN KS. THIS MAGNITUDE OF BUOYANCY
AND MIDLEVEL LAPSE RATES IN EXCESS OF 8 C/KM ARE SUPPORTIVE OF A FEW
STORMS WITH LARGE HAIL...THOUGH CONVECTIVE INHIBITION ASSOCIATED
WITH THE ELEVATED MIXED LAYER MAY ALSO LIMIT STORM COVERAGE IN THE
AREA OF STRONGEST INSTABILITY.
OTHERWISE...ISOLATED SURFACE-BASED STORMS MAY FORM TODAY ALONG THE
WARM FRONT IN CENTRAL TX...AS WELL AS OVER THE DAVIS MOUNTAINS IN SW
TX. INSTABILITY AND DEEP-LAYER VERTICAL SHEAR WILL BE SUFFICIENT
FOR ORGANIZED STORMS CAPABLE OF PRODUCING SOME HAIL AND GUSTY WINDS.
STORM COVERAGE SHOULD REMAIN RATHER SPARSE GIVEN LINGERING
CONVECTIVE INHIBITION AND ONLY SHALLOW ASCENT ALONG THE FRONT...OR
WEAK UPSLOPE INTO THE HIGHER TERRAIN OF SW TX.
..THOMPSON/HURLBUT.. 05/09/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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