MESOSCALE PRECIPITATION DISCUSSION 0525
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
532 AM EDT MON SEP 28 2015
 
AREAS AFFECTED...LOWER AL/WESTERN FL PANHANDLE... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 280931Z - 281301Z
 
SUMMARY...A PAIR OF MOISTURE CHANNELS CONTINUE TO PUMP HIGH PWAT
AIR NORTHWARD INTO THE EASTERN GULF COAST. WHILE MUCH OF THE
DEEPER CONVECTION HAS REMAINED OFFSHORE OVERNIGHT...THE
ENVIRONMENT IS CONDUCIVE TO HIGH RAINFALL RATES CAPABLE OF
PRODUCING FLASH FLOODING...PARTICULARLY IN LOW LYING AREAS.

DISCUSSION...SATELLITE IMAGERY THIS MORNING SHOWED A WELL DEFINED
NORTH-SOUTH CONVECTIVE PLUME CONTAININED MULTIPLE EMBEDDED
FLARE-UPS. IT REMAINS TO BE SEEN IF THE BETTER BUOYANCY CAN WORK
ITS WAY INLAND EARLY THIS MORNING. THERE DOES APPEAR TO BE A
DECENT FOCUS AT THE SURFACE WITH A WELL DEFINED EAST-WEST BOUNDARY
ORIENTED ALONG THE COASTLINE. DUAL-POL HOURLY RAINFALL ESTIMATES
SUGGEST 1 TO 2 INCH RATES IN THE OFFSHORE WATERS. IF ANY OF THESE
CONVECTIVE ELEMENTS CAN WORK THEIR WAY INLAND...THEY COULD CAUSE
ISOLATED ISSUES...PARTICULARLY IN LOCATIONS SUSCEPTIBLE TO FLASH
FLOODING.

THE BIGGEST WILDCARD WILL BE THE LACK OF INSTABILITY WITH THE 09Z
RAP OBJECTIVE ANALYSIS SUGGESTING MUCAPES IN THE 500 TO 750 J/KG
RANGE. AS MENTIONED EARLIER...MOISTURE WILL NOT BE AN ISSUE GIVEN
2 TO 2.25 INCH PWATS SPREADING THROUGH THE REGION WITH EMBEDDED
SHORTWAVES CONTINUING TO TRIGGER CONVECTION OVER THE EASTERN GULF
OF MX. THERE ARE SOME RATHER WET SOLUTIONS AMONG THE RECENT
GUIDANCE...ESPECIALLY THE 00Z GEM REGIONAL. THE SIGNAL IS FUZZY
AMONG MANY OF THE CAMS BUT DO MAINTAIN A HEAVY RAINFALL THREAT
THROUGH THE MORNING HOURS.


RUBIN-OSTER

ATTN...WFO...MOB...TAE...

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

LAT...LON   31508752 31458625 30878536 30028555 29448649 
            29478729 29888795 30958820