MESOSCALE PRECIPITATION DISCUSSION 0029...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1103 AM EDT THU MAY 02 2013
 
AREAS AFFECTED...SOUTHERN GA AND NORTHEASTERN FL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
 
VALID 021457Z - 022057Z
 
SUMMARY...PERSISTENT BANDS OF THUNDERSTORM ACTIVITY MOVING INTO
SOUTHEAST GA AND NORTHEAST FL COULD LEAD TO FLASH FLOODING DURING
THE DAY TODAY.

DISCUSSION...RECENT RADAR IMAGERY SHOWS A COUPLE BANDS OF
CONVECTION, INITIATED BY AN OFFSHORE INVERTED TROUGH/COASTAL FRONT
WHICH THEN EXTEND INLAND WITHIN AN AXIS OF HIGHER PRECIPITABLE
WATER (PW) VALUES IN EXCESS OF 1.50 INCHES.  A COUPLE ISOLATED
SPOTS HAVE RECEIVED AROUND TWO INCHES OF RAIN SINCE 12Z/8 AM EDT,
AND THESE TYPE OF RAINFALL RATES SHOULD CONTINUE TO BE POSSIBLE
WITHIN THE BANDS OF CONVECTION FROM TIME TO TIME DURING THE DAY
TODAY.  THE 850 HPA INFLOW WITHIN THIS AREA IS 30-35 KNOTS, AND
RECENT RAP RUNS INDICATE THAT THE BEST LOW-LEVEL INFLOW COULD
SHIFT SLOWLY SOUTHWARD WITH TIME, WHICH WOULD INCREASINGLY FAVOR
THE SOUTHERN PORTION OF THE AREA IN NORTHEAST FL.  SO FAR, THE 00Z
NMM APPEARS TO BE DOING A REASONABLE JOB WITH THE PRECIPITATION
FORECAST IN THIS REGION, WITH THE LAST FEW RAP RUNS MISSING THE
BOAT ON THE SOUTHEAST GEORGIA ACTIVITY.  DIVERGENCE ALOFT IS
ACTING AS AN EFFECTIVE VENTILATION MECHANISM FOR THE ONGOING
CONVECTION, AND PRECIPITATION IN THIS AREA IS EXPECTED TO HAVE
LONG DURATION, WHICH SHOULD CONTINUE SATURATING SOILS AND DROPPING
FLASH FLOOD GUIDANCE (FFGS) IN THIS AREA.  EARLY MORNING
CONVECTION HAS ALREADY DROPPED FFGS TOWARDS 2.5 INCHES WITHIN
THREE HOURS' TIME IN A SEVERAL SMALL SPOTS WITHIN THE DEPICTED
REGION.  LOCAL RAINFALL AMOUNTS OF 2-4 INCHES ARE EXPECTED WITHIN
A SHORT TIME FRAME, WHICH COULD LEAD TO FLASH FLOODING IN
NORTHEAST FL AND SOUTHEAST GA THROUGH EARLY THIS AFTERNOON.

ROTH


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

LAT...LON   29408109 29538171 30298210 31248189 31648118 30488130
            29408109