MESOSCALE PRECIPITATION DISCUSSION 0022
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
759 AM EDT SUN APR 28 2013
 
AREAS AFFECTED......NORTHEASTERN AL/NORTHERN GA/EASTERN TN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 281159Z - 281429Z
 
SUMMARY...STRONG CONVECTION MAINTAINED FROM OVERNIGHT ACTIVITY
WILL BRING A THREAT FOR FLASH FLOODING OVER AREAS OF NORTHERN
GEORGIA THIS MORNING.

DISCUSSION...A NOCTURNAL COMPLEX OF SHOWERS AND THUNDERSTORMS
APPEARS TO HAVE MAINTAINED ITS INTENSITY PER IR SATELLITE TRENDS
AND LIGHTNING DATA. THERE IS LITTLE REASON TO BELIEVE THIS AXIS OF
CONVECTION WILL WEAKEN DURING THE NEXT FEW HOURS AS THE
PRECIPITATION MOVES ACROSS AN AREA OF DIMINISHED 3-HOUR FFG
VALUES. IT APPEARS THIS THREAT SHOULD MOVE JUST TO THE NORTH OF
THE ATLANTA METRO AREA. THE 850-MB FLOW IS FORECAST TO PUMP SOME
OF THE HIGHER MOISTURE CONTENT OUT OF THE GULF OF MEXICO INTO THE
LOWER TENNESSEE VALLEY. ADDITIONALLY...MOST OF THE HIGH-RESOLUTION
GUIDANCE SUGGESTS THIS AREA WILL BE IMPACTED BY 1 TO 2 INCH
RAINFALL TOTALS IN 6 HOURS WITH LOCALIZED HIGHER AMOUNTS. THIS
SUPPORT INCLUDES THE 00Z SPC WRF/00Z HIGH-RES WRF-NMM ALONG WITH
DETERMINISTIC RUNS FROM THE 06Z NAM/GFS.

RUBIN-OSTER


ATTN...WFO...GSP...MRX...FFC...BMX...HUN...

LAT...LON   34098635 34778587 35058520 35088426 34818336 34278309
            34008329 34078448 33668577 34098635