Post by SKYSUMMIT on Mar 30, 2008 7:11:12 GMT -6
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0744 AM CDT SUN MAR 30 2008
VALID 301300Z - 311200Z
...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM E TX INTO LA...
...THERE IS A SLGT RISK OF SVR TSTMS THIS EVENING INTO TONIGHT FROM
NW OK TO THE NE KS/NW MO AREA...
...NW OK/SW KS LATE THIS EVENING...
A SURFACE COLD FRONT WILL CONTINUE TO DRIFT SWD ACROSS KS IN THE
WAKE OF A STRONG MID LEVEL TROUGH EJECTING NEWD OVER WRN ONTARIO. S
OF THIS BOUNDARY...A MOIST LOW-LEVEL AIR MASS /BOUNDARY LAYER
DEWPOINTS OF 64-68 F/ WILL SPREAD NWD ACROSS TX/OK/SRN KS DURING THE
DAY. LOW CLOUDS MAY SLOW SURFACE HEATING WITHIN THE MOIST AIR
MASS...BUT STRONGER SURFACE HEATING ALONG A DEVELOPING DRYLINE NEAR
THE WRN OK/TX BORDER WILL COMBINE WITH THE INCREASING MOISTURE AND
STEEP MID LEVEL LAPSE RATES TO SUPPORT MLCAPE VALUES OF 1500-2500
J/KG THIS AFTERNOON/EVENING ACROSS NW TX AND CENTRAL/WRN OK.
THE PRIMARY UNCERTAINTY FOR THIS AREA WILL BE WHETHER OR NOT
SURFACE-BASED CONVECTIVE INITIATION WILL OCCUR BY THIS EVENING.
WATER VAPOR IMAGERY SHOWS A WEAK LEAD SHORTWAVE TROUGH OVER THE
LOWER CO RIVER VALLEY THAT EXTRAPOLATES TO THE WRN KS VICINITY BY
LATE THIS EVENING. THIS FEATURE SHOULD BE RELATIVELY DIFFUSE AND
CONVECTIVE INITIATION WILL LIKELY RELY ON AFTERNOON TEMPERATURES IN
THE LOW-MID 80S TO MINIMIZE CONVECTIVE INHIBITION ALONG THE DRYLINE
AND NEAR THE SURFACE TRIPLE POINT...AS WELL AS LOW-LEVEL ASCENT
ALONG THE SLOW MOVING FRONT ENE OF THE TRIPLE POINT. IF DEEP
CONVECTION CAN DEVELOP PRIOR TO NOCTURNAL STABILIZATION OF THE
NEAR-SURFACE LAYER...A PRONOUNCED INCREASE IN THE SLY LLJ AND
ASSOCIATED LOW-LEVEL SHEAR FROM 00-03Z WILL CONTRIBUTE TO FAVORABLE
VERTICAL SHEAR FOR TORNADIC SUPERCELLS THE FIRST HALF OF TONIGHT.
VERY LARGE HAIL WILL BE POSSIBLE WITH ANY SUPERCELLS...AS WELL.
...CENTRAL/NE KS INTO NW MO LATE TONIGHT...
THE FRONT WILL LIKELY RETREAT NWD ACROSS NE KS/NW MO LATE TONIGHT IN
RESPONSE TO CYCLOGENESIS ACROSS CENTRAL/NE KS...IN ADVANCE OF THE
PRIMARY MID LEVEL WAVE /NOW JUST OFF THE CENTRAL CA COAST/ THAT WILL
BEGIN TO EMERGE OVER THE HIGH PLAINS FROM 06-12Z. INCREASING
LOW-LEVEL WAA ON THE NOSE OF A 40-50 KT LLJ SHOULD SUPPORT ELEVATED
THUNDERSTORM DEVELOPMENT OVERNIGHT ALONG AND N OF THE SURFACE
BAROCLINIC ZONE. STEEP MID LEVEL LAPSE RATES AND AN INFLUX OF RICH
MOISTURE FROM THE S WILL SUPPORT MUCAPE VALUES OF 1500-2000 J/KG
OVERNIGHT...AND THE POTENTIAL FOR LARGE HAIL WITH ELEVATED
SUPERCELLS.
...E/NE TX AND LA TODAY...
A LARGE AREA OF ELEVATED THUNDERSTORMS HAS PERSISTED OVERNIGHT
ACROSS AR/MO...WITH RENEWED DEVELOPMENT OVER E/NE TX THE PAST COUPLE
OF HOURS. THIS CONVECTION APPEARS TO BE REINFORCING THE BAROCLINIC
ZONE FROM NE TX INTO NRN LA/SRN AR AND NW MS. EXPECT ADDITIONAL
THUNDERSTORMS TO FORM DURING THE DAY ALONG THE PRIMARY FRONT AND A
SECONDARY DIFFUSE MARINE WARM FRONT FROM E TX INTO LA...IN ADVANCE
OF A WEAK MID LEVEL SHORTWAVE TROUGH MOVING ENEWD FROM CENTRAL/E TX.
RICH LOW-LEVEL MOISTURE AND THE RESIDUAL ERN EXTENT OF THE ELEVATED
MIXED LAYER OVER TX/OK WILL SUPPORT MODERATE INSTABILITY AND STRONG
UPDRAFTS CAPABLE OF PRODUCING ISOLATED LARGE HAIL.
..THOMPSON/SMITH.. 03/30/2008
