SPC AC 151933
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0233 PM CDT SUN MAR 15 2009
VALID 152000Z - 161200Z
...NO SVR TSTM AREAS FORECAST...
...GULF COASTAL STATES...
BROAD SWLY FLOW ALOFT COVERED THE REGION THIS AFTERNOON WITH AREAS
OF CONVECTION ACROSS PORTIONS OF WRN FL/SERN AL/SWRN GA AND ALSO IN
THE TX GULF COSTAL PLAINS/NWRN GULF. AT THE SAME TIME...WATER VAPOR
IMAGERY SHOWED AN UPPER IMPULSE MOVING RAPIDLY NEWD INTO THE SRN
APPALACHIANS...WHILE A POSITIVELY-TILTED TROUGH WAS LOCATED OVER THE
SRN PLAINS. A QUASI-STATIONARY COLD FRONT STRETCHED WWD FROM THE
GA/SC BORDER TO THE AL/GA BORDER...AND THEN SWWD INTO THE EXTREME
WRN FL PANHANDLE. CONVECTION LOCATED NEAR THIS BOUNDARY IS EXPECTED
TO SLOWLY DIMINISH THROUGH THE AFTERNOON AS THE UPPER WAVE SHIFTS
NEWD AWAY FROM THE REGION AND LOW LEVEL MASS CONVERGENCE WEAKENS.
DESPITE MUCAPES BETWEEN 500-1000 J/KG AND VEERING WIND PROFILES...
WEAKENING FORCING SUGGESTS THAT THE SEVERE THREAT IS WANING.
PCPN/CONVECTION OVER SERN TX/NWRN GULF IS EXPECTED TO SLOWLY EXPAND
ENEWD OVERNIGHT WITHIN ZONE OF ISENTROPIC LIFT LOCATED AHEAD OF
UPPER TROUGH. HOWEVER...THE UPDRAFT ROOTS WILL BE SITUATED ABOVE THE
COOLER BOUNDARY LAYER...BETWEEN 850-900 MB. THE ELEVATED NATURE OF
THE CONVECTION PLUS WEAK MID LEVEL LAPSE RATES AND MARGINAL
INSTABILITY...AOB 250 J/KG...INDICATES THE THREAT FOR SEVERE STORMS
SHOULD BE QUITE LOW.
..IMY.. 03/15/2009
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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