SPC AC 251251
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0651 AM CST WED NOV 25 2009
VALID 251300Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PROGRESSIVE BUT INCREASINGLY AMPLIFIED PATTERN WILL PREVAIL THIS
PERIOD...AS DAKOTAS SHORTWAVE TROUGH EVOLVES INTO A DEEP CLOSED LOW
OVER IL/IND...AND UPSTREAM RIDGE MOVES FROM THE PACIFIC NW TO THE
NRN RCKYS. IN THE SRN STREAM...IMPULSE NOW OVER THE CNTRL GULF OF
MEXICO EXPECTED TO ACCELERATE ENE ACROSS FL AND THE WRN ATLANTIC
LATER TODAY/TONIGHT AS WSWLY FLOW STRENGTHENS ON SE SIDE OF
AMPLIFYING MS VLY TROUGH.
AT THE SFC...CURRENT ANALYSIS DEPICTS A WEAK FRONT EXTENDING ENE
ACROSS S FL FROM A SFC WAVE ABOUT 75 MILES WSW OF FMY. THE WAVE
SHOULD REFORM ALONG OR JUST OFF THE E FL CST /NEAR VRB/ LATER THIS
MORNING...BEFORE CONTINUING NE OFF THE FL CST TONIGHT. FARTHER
S...STNRY OUTFLOW BOUNDARY ORIENTED ROUGHLY PARALLEL TO THE FL KEYS
LIKELY WILL PERSIST UNTIL WAVE MOVES OFF THE E FL CST LATER TODAY.
...S FL...
WIDESPREAD DEEP CONVECTION AND SCTD TSTMS EXPECTED OVER THE SERN
THIRD OF THE FL PENINSULA TODAY IN AREA OF PERSISTENT LOW LVL WAA/
MOISTURE INFLOW NEAR AFOREMENTIONED SFC WAVE. WINDS AS SHOWN BY
AREA VAD PROFILES HAVE GRADUALLY INCREASED DURING THE OVERNIGHT.
MODERATE SPEEDS WITH CONSIDERABLE LOW LVL VEERING NOW PRESENT ARE
SUPPORTIVE SUSTAINED STORMS/WEAK SUPERCELLS...GIVEN FAVORABLE LOW
LVL FORCING. WINDS MAY STRENGTHEN A BIT MORE THROUGH ABOUT MIDDAY
AS GULF IMPULSE CONTINUES ENEWD...BUT A SUBSTANTIAL INCREASE IS NOT
EXPECTED. PW WILL REMAIN HIGH...WITH VALUES AROUND 2.00 INCHES.
OVERALL...SETUP WILL REMAIN FAVORABLE FOR CLUSTERS OF
LOOSELY-ORGANIZED STORMS OVER S FL TODAY...WITH POCKETS OF
STRONGER/MORE SUSTAINED ACTIVITY. GIVEN HIGH PW AND MODEST
SHEAR...THE THREAT FOR LOCALLY DMGG WIND GUSTS AND AN ISOLD TORNADO
WILL CONTINUE. THIS THREAT WILL BE GREATEST THROUGH ABOUT
MIDDAY/EARLY AFTN ALONG THE SE CST FROM NEAR VRB S TO MIA. THE RISK
DOES NOT APPEAR GREAT ENOUGH TO WARRANT A SLGT RISK ATTM GIVEN WEAK
LOW TO MID LVL LAPSE RATES AND MODEST SHEAR.
..CORFIDI/JEWELL.. 11/25/2009
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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