Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 021539
FFGMPD
FLZ000-022000-

MESOSCALE PRECIPITATION DISCUSSION 0406
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1138 AM EDT SUN AUG 02 2015

AREAS AFFECTED...NORTHERN AND CENTRAL FLORIDA

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

VALID 021530Z - 022000Z

SUMMARY...WEAK LAPSE RATES AND OFFSHORE DEVELOPMENT LIMITING
OVERALL COVERAGE THREAT TO CONVERGENT BANDS...THOUGH WARM PROCESS
AND HIGH MOISTURE COULD PRODUCE SMALL AREAS OF POSSIBLE FLASH
FLOODING

DISCUSSION...CONVECTIVE COMPLEX OFFSHORE NEAR 28.4N 84.6W
(SOUTHWEST OF APALACHEE BAY) PRODUCED ENOUGH LATENT HEAT RELEASE
ALOFT FOR PRESSURE FALLS TO DEVELOP A NEW SURFACE INFLECTION.
THIS HAS ROBBED MUCH OF THE CONVERGENCE TO THE NORTHERN BAND
NEARER THE MAIN SURFACE LOW HUGGING THE COASTLINE....REDUCING
CONVECTIVE DEVELOPMENT HERE.   THIS SCENARIO DIVERGES FROM MUCH OF
THE HIGH RESOLUTION MODEL GUIDANCE INDICATING THE HIGHEST TOTALS
TO BE DROPPING SOUTH ALONG THE NORTHEAST FL GULF COAST THIS
EVENING...THOUGH WITH A VERY HIGH MOISTURE ENVIRONMENT (TPWS STILL
IN THE 2.25-2.4" RANGE) AND STRONG WIND FLOW REGIME...FLOODING
POTENTIAL STILL EXISTS THOUGH WITH A BIT LESS CONFIDENCE IN ANY
PARTICULAR SCENARIO.

CONSIDERING THE DAYS OF WORKED OVER ENVIRONMENT...LAPSES RATES PER
12Z TBW ARE QUITE WEAK AND SO STRONG SURFACE OR LOW LEVEL DEEP
MOISTURE CONVERGENCE WILL BE REQUIRED TO MAINTAIN CONVECTION FOR
PROLONGED FLASH FLOODING THREAT. CURRENTLY SURFACE CONFLUENCE
EXISTS ON THE OUTER FEEDER BAND FROM THE SURFACE TROF STRONG
WESTERLY FLOW INTERSECTING WITH SOUTHERLY FROM THE
EASTERLIES....SOUTHWEST OF TAMPA BAY ACROSS CENTRAL FL.  THOUGH
GENERALLY WEAK GIVEN 5-10 KTS OF FLOW FROM DEEPER TROPICS...IT IS
ENOUGH FOR A BAND TO BE ESTABLISHED...AND GIVEN CELL MOTION IS
GENERALLY PARALLEL TO THIS BAND FOR SOME TRAINING TO OCCUR ALONG
IT...POTENTIALLY ACROSS AREAS AFFECTED LAST EVENING.

WITH THE STRENGTHENING OF THE NEW SURFACE LOW...WINDS WILL BACK
TOWARD THE LOW AND GENERATE A NW-SE CONVERGENCE BAND FROM THE LOW
TOWARD THE INTERSECTION OF THE OUTER BAND DESCRIBED ABOVE...THIS
WILL ALLOW FOR INCREASED CONVECTIVE DEVELOPMENT TO INITIATE JUST
OFFSHORE FROM TAMPA NORTHWARD WITH PROLONGED REGENERATION
UPSTREAM...TO ALLOW FOR TRAINING ALONG THE COAST AND JUST INLAND
OVER THE NEXT FEW HOURS.


GALLINA

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

ATTN...WFO...JAX...MLB...TAE...TBW...

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

LAT...LON   30078258 29498176 29318095 28698080 27768124
            26888177 26648231 27098294 27668296 28318292
            28878296 29148341 29488352 29728331


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