MESOSCALE PRECIPITATION DISCUSSION 0033...CORRECTION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1235 PM EDT FRI MAY 03 2013
 
AREAS AFFECTED...NORTHEAST FL AND SOUTHEAST GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 031634Z - 032234Z
 
SUMMARY...A LOW PRESSURE AREA OFFSHORE DAYTONA BEACH COULD MOVE
INLAND INTO NORTHEAST FLORIDA OVER THE NEXT SEVERAL HOURS, LEADING
TO FLASH FLOODING ACROSS THE REGION.

DISCUSSION....SIGNIFICANT DIVERGENCE ALOFT CONTINUES TO EXIST
ACROSS NORTHEAST FL AND THE ADJACENT SUBTROPICAL ATLANTIC, AND IS
EXPANDING NORTHWARD ALONG THE GA COAST.  A SURFACE LOW PRESSURE
SYSTEM IS CURRENTLY OFFSHORE DAYTONA BEACH HAS SLOWED DOWN ITS
NORTHWARD PROGRESSION, AND MAY MOVE INLAND INTO NORTHEAST FLORIDA
OVER THE NEXT SEVERAL HOURS.  THIS WOULD DRAG RAINFALL RATES OF
4"+ WITHIN THREE HOURS INTO THE SCALLOPED AREA, WHICH WOULD EXCEED
FLASH FLOOD GUIDANCE VALUES (FFGS) ANYWHERE WITHIN THIS REGION. 
EVEN IF THE LOW PRESSURE SYSTEM STAYS OFFSHORE, CONVECTION SHOULD
CONTINUE TO MOVE WEST-NORTHWESTWARD INTO COASTAL AREAS OF
NORTHEAST FL OVER THE NEXT SEVERAL HOURS ON THE HEELS OF 55-65
KNOT LOW-LEVEL WINDS, PER OBSERVATIONS FROM THE AIR FORCE WIND
TOWERS AT CAPE CANAVERAL AND THE MESOSCALE GUIDANCE, WHICH ARE
MAINLY DIRECTED TOWARDS THE FL/GA BORDER.  THE MESOSCALE GUIDANCE
IS NOT IMPRESSED WITH THIS RAINFALL BAND AS OF LATE, INDICATING
THAT IT SHOULD BE WEAKENING QUICKLY.  WITH FFGS LOCALLY DOWN BELOW
1.5"/3 HOURS, FLASH FLOODING IS LIKELY ACROSS NORTHEAST FLORIDA. 
THE AREA WAS EXTENDED NORTHWARD FROM MPD #31 TO ACCOUNT FOR A NEW
BAND OF SHOWERS AND THUNDERSTORMS WHICH HAS RECENTLY DEVELOPED AND
MOVED INTO THE BRUNSWICK GA AREA, WHERE FFGS ARE LOCALLY DOWN TO
2.5" WITHIN THREE HOURS.

ROTH


ATTN...WFO...CHS...MLB...JAX...

LAT...LON   30048251 30988233 31778166 31818101 30858092 29598061
            28718026 28418060 29308208 30048251