MESOSCALE PRECIPITATION DISCUSSION 0693
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
313 PM EST THU DEC 24 2015
 
AREAS AFFECTED...CNTRL GULF COAST INTO SRN MISSISSIPPI...ALABAMA
AND WRN GEORGIA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 242012Z - 250212Z
 
SUMMARY...PLASH FLOODING WILL REMAIN LIKELY THROUGH
00Z...ESPECIALLY OVER SATURATED SOILS FROM EARLIER
RAINFALL...ACROSS PORTIONS OF THE CNTRL GULF COAST INTO THE
CNTRL/SRN ALABAMA/GEORGIA BORDER.
 
DISCUSSION...20Z SURFACE OBSERVATIONS AND VISIBLE SATELLITE
IMAGERY SHOWED A RAIN COOLED BOUNDARY EXTENDING WEST-EAST JUST
NORTH OF THE CNTRL GULF COAST. WITH SURFACE TEMPERATURES WARMING
INTO THE LOWER 80S SOUTH OF THIS BOUNDARY...THERE ALSO APPEARS TO
BE SOME SEA BREEZE ENHANCEMENT...ALTHOUGH STRONG LOW LEVEL FLOW IS
DOMINATING THE NWD MOVEMENT OF THIS BOUNDARY. WATER VAPOR IMAGERY
INDICATED A LOW AMPLITUDE SHORTWAVE APPROACHING FROM THE N-CNTRL
GULF OF MEXICO...WITH THE NRN FRINGES ALREADY IMPACTING THE GULF
COAST REGION WITH RADAR ECHOES EXTENDING WEST TO ERN LOUISIANA.
250 MB WINDS SHOW ENHANCEMENT TO THE TUNE OF 70+ KTS WITH THE
SHORTWAVE...CONFIRMED VIA GOES HD WINDS...WHICH ARE APPROACHING
THE GULF COAST AND INCREASING UPPER LEVEL DIVERGENCE. LOW LEVEL
FLOW HAS SHOWN SLIGHT WEAKENING OVER THE PAST 3 HOURS BUT IS
EXPECTED TO REMAIN SUFFICIENTLY STRONG TO CONTINUE AN INFLUX OF
DEEP MOISTURE INTO THE REGION. 

MEAN CELL MOTIONS HAVE BEEN TOWARD THE NORTHEAST AT 25-30
KTS...AND 850-700 MB FLOW IS FORECAST TO REMAIN NEAR OR JUST ABOVE
THIS MAGNITUDE WHICH SHOULD CONTINUE TO PROMOTE TRAINING CELLS
THROUGH 00Z. THE GREATEST CONCERN IS WHERE 6 HR RAINFALL ENDING AT
19Z HAS AVERAGED 3-6 INCHES ACROSS SERN ALABAMA. HOWEVER...AS THE
AREA OF ONGOING RAINS OVER SRN MISSISSIPPI/ALABAMA SLOWLY SHIFT
NORTH WITH THE APPROACH OF THE SHORTWAVE...TRAINING POTENTIAL MAY
CAUSE FLASH FLOODING ACROSS LOCATIONS INTO CNTRL ALABAMA AND
PORTIONS OF ERN MISSISSIPPI.

OTTO

ATTN...WFO...BMX...FFC...JAN...MOB...TAE...

ATTN...RFC...LMRFC...SERFC...

LAT...LON   33948412 33388377 32518386 31328536 30928679 
            31028853 31388946 32008971 32528886 33128727 
            33908547