MESOSCALE PRECIPITATION DISCUSSION 0525
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
920 AM EDT FRI AUG 05 2016
 
AREAS AFFECTED...EASTERN FL PANHANDLE/WEST-CENTRAL FL COAST... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 051320Z - 051750Z
 
SUMMARY...EARLY MORNING CONVECTION CONTINUES TO FIRE IN RESPONSE
TO A WEAK/PERSISTENT BAND OF MID-LEVEL VORTICITY ACROSS THE
NORTHEASTERN GULF OF MX. DEEP TROPICAL MOISTURE REMAINS OVER THE
REGION WITH PWATS OVER 2.25" ACROSS MUCH OF THE NORTHERN HALF OF
FL. VERY WEAK STEERING FLOWS SHOULD ALLOW FOR SLOW MOVING
CONVECTION WITH CELL MERGERS INCREASING THE RISK FOR FLASH
FLOODING.

DISCUSSION...VISIBLE IMAGERY THIS MORNING SHOWED SEVERAL
CONVECTIVE COMPLEXES ERUPTING ALONG THE NORTHWEST FL COAST. THE
12Z SOUNDING FROM TLH INDICATED DEEP TROPICAL MOISTURE IN PLACE
WITH PWATS NEARING 2.50 INCHES. ADDITIONALLY...TALL/SKINNY CAPE
PROFILES WERE NOTED COUPLED WITH VERY WEAK TROPOSPHERIC FLOW AND
FREEZING LEVELS ABOVE 15 KFT. ALL OF THESE INGREDIENTS SUPPORT
HEAVY RAINFALL ACROSS THE AFFECTED REGION. WHILE MOST OF THE CB
TOWERS WERE LOCATED ALONG THE COAST OR JUST OFFSHORE...VAD WIND
PROFILER DATA SHOWED DECENT LOW-LEVEL WESTERLY FLOW WHICH SHOULD
DRAW SOME OF THESE STORMS INLAND. AS OF 13Z...THE PROFILER DATA
INDICATED 10 TO 15 KNOTS OF WESTERLY FLOW IN THE 3000 TO 6000 FT
LAYER. THERE DOES NOT APPEAR TO BE ANY NOTABLE INHIBITION IN THE
RAP OBJECTIVE ANALYSIS WHICH IS BEING VERIFIED BY THE FREE
CONVECTION OCCURRING OVER MUCH OF THE NORTHEASTERN GULF OF MX.

AS USUAL...THE FLASH FLOOD GUIDANCE VALUES ARE RATHER HIGH OVER
THE REGION WHICH WOULD MAKE EXCEEDANCE OF THESE NUMBERS DIFFICULT.
HOWEVER...ANY ORGANIZED/SLOW-MOVING CELLS WITHIN THIS EXTREMELY
HIGH PWAT/WEAK SHEAR ENVIRONMENT CAN PRODUCE HEAVY DOWNPOURS
CAPABLE OF FLASH FLOODING.

THERE IS A DECENT SIGNAL IN THE CAMS FOR ORGANZED HEAVY RAINFALL
OVER THE REGION...PARTICULARLY ALONG THE COAST WHERE LOW-LEVEL
CONVERGENCE WILL BE MAXIMIZED. THE 00Z NSSL-WRF CONFINES THE
ACTIVITY TOWARD THE SOUTH WHILE THE LATEST HRRR/HRRR-PARALLEL SEEM
TO EVENLY DISTRIBUTE THE CONVECTION ALONG THE COAST.


RUBIN-OSTER

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

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

LAT...LON   30298393 30208302 29658256 29258245 28588241 
            28038257 28118319 28848336 29208360 29868424