SPC AC 251250
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0650 AM CST FRI DEC 25 2009
VALID 251300Z - 261200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE S ATLANTIC
CST...
...SYNOPSIS...
INTENSE IL UPR VORT EXPECTED TO PIVOT NNW INTO IA TODAY AS UPSTREAM
SW NEB LOW SHEARS ESE INTO KS/MO. AS A RESULT...THE STRONGEST
HEIGHT FALLS WILL SPREAD SLOWLY NE ACROSS THE OH VLY/GRT
LKS...ALTHOUGH MODEST FALLS WILL OVERSPREAD GA AND THE CAROLINAS AS
REGION IS GLANCED BY TROUGH EXTENDING SE FROM THE IL VORT.
AT THE SFC...DEEP SFC LOW OVER IA SHOULD CONTINUE TO OCCLUDE AND
DRIFT SLOWLY NNW WHILE ASSOCIATED COLD FRONT MOVES STEADILY ENE
ACROSS GA AND THE CAROLINAS. WEAK TRIPLE POINT WAVE NOW OVER E
CNTRL GA MAY EVOLVE INTO A DISTINCT SFC LOW LATER TODAY/TONIGHT
OVER THE ERN CAROLINAS...AND REACH SE VA EARLY SAT.
...N FL/ERN GA INTO THE CAROLINAS...
50-60 KT SWLY 500 MB FLOW WILL PREVAIL ATOP MOISTENING WARM SECTOR
OVER THE SC CSTL PLNS AND ERN GA THIS MORNING...AHEAD OF GA/NW FL
COLD FRONT. ALTHOUGH STORMS THAT INTENSIFIED AHEAD OF THE FRONT
EARLIER THIS MORNING HAVE SINCE WEAKENED...POTENTIAL WILL EXIST FOR
A FEW SUSTAINED STORMS/POSSIBLE SUPERCELLS ALONG AND AHEAD OF THE
BOUNDARY THROUGH ABOUT MIDDAY GIVEN STRENGTH OF SHEAR AND PRESENCE
OF AT LEAST WEAK FORCING FOR ASCENT.
WARM LAYER AROUND 700 MB /PER JAX AND CHS 12Z RAOBS/ AND NWD
MOVEMENT OF UPR TROUGH/VORT SHOULD LIMIT OVERALL SVR THREAT. BUT
PERSISTENT AIR MASS MODIFICATION IN STRONGLY SHEARED/WEAKLY
CONVERGENCE ENVIRONMENT MAY PROVE SUFFICIENT TO POSE A THREAT FOR
ISOLD TORNADOES AND/OR DMGG WIND GUSTS. THIS THREAT SHOULD BE
GREATEST OVER ERN GA AND THE SC/SRN NC CSTL PLN THROUGH MIDDAY/EARLY
AFTN...WHERE SFC DEW POINTS WILL BE IN THE LOW-MID 60S F AND 0-1 KM
SRH WILL BE AOA 300 M2/S2. A MORE LIMITED THREAT MAY PERSIST OVER
FAR ERN NC INTO THIS EVE IN CONJUNCTION WITH DEVELOPING SFC WAVE.
FARTHER S...SVR THREAT SHOULD DIMINISH ALONG TRAILING CONVERGENCE
ZONE OVER THE NERN GULF AND WRN FL AS WARMING CONTINUES ALOFT...AND
UPR FORCING FOR ASCENT CONTINUE NEWD AWAY FROM REGION.
..CORFIDI.. 12/25/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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