Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 150806
FFGMPD
GAZ000-FLZ000-151305-

MESOSCALE PRECIPITATION DISCUSSION 0023
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
405 AM EDT TUE APR 15 2014

AREAS AFFECTED...NRN FL...FAR SRN GA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 150805Z - 151305Z

SUMMARY...THE WEST TO EAST OREINTED PORTION OF AN OUTFLOW BOUNDARY
WILL INTERCEPT LOW LEVEL INFLOW...LEADING TO CONTINUED HEAVY RAIN
AND SOME THREAT OF ADDITIONAL FLASH FLOODING.

DISCUSSION...OBSERVATIONS ALONG WITH SIGNALS IN THE MODEL MASS AND
QPF FIELDS SUGGEST A CONTINUED THREAT OF HEAVY RAIN AND SPOTTY
FLASH FLOODING THROUGH AT LEAST 12Z. THE RAP AND HRRR FORECAST THE
CAPE AXIS TO BLEED EASTWARD AT THE SAME PACE AS THE SLOW MOVING
CONVECTION AND UPSTREAM TROUGH/FRONTAL ZONE. THE DIURNAL WEAKENING
TREND OF CONVECTIVE INTENSITY...NOTED IN RECENT WARMING CLOUD
TOPS...WILL BE OFFSET BY STRONG INFLOW OFF THE WARM GULF AND
SUSTAINED MID LEVEL ASCENT. AS OF 08Z THERE HAD BEEN NO
APPRECIABLE DECREASE IN THE BREADTH OF THE HEAVY RADAR
ECHOES...ONLY GRADUAL WEAKENING WITH EASTWARD EXTENT AWAY FROM THE
CAPE AXIS.

WITH PLENTY OF ADDITIONAL CONVECTION STILL FORMING OVER THE
NORTHERN GULF...THE MAIN CONCERN IS THAT THE WEST TO EAST ORIENTED
PORTION OF THE OUTFLOW BOUNDARY WILL INTERCEPT CELLS AS THEY MOVE
INLAND AND FOCUS THE INTENSE RAIN RATES FOR LONGER
DURATIONS...GENERALLY NEAR INTERSTATE 10. GIVEN EARLIER ISOLATED
REPORT OF 3.83 INCHES IN ONE HOUR...AND MORE GENERALLY OBSERVED
2-3 INCH AMOUNTS OVER 1-2 HOURS...THERE IS STILL SOME CHANCE OF
EXCEEDING THE LARGE ONE AND THREE HOUR FLASH FLOOD GUIDANCE VALUES
IN THIS REGION...AND ANY URBANIZED OR POORLY DRAINED AREAS WILL BE
EVEN MORE SUSCEPTIBLE TO FLASH FLOODING.

BURKE

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...JAX...TAE...

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

LAT...LON   31058371 30978453 30908500 30628595 30128611 29588567
            29488455 29688373 30098288 30698250 31028313 31058371



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