MESOSCALE PRECIPITATION DISCUSSION 0309
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 AM EDT WED JUN 07 2017

AREAS AFFECTED...FL PANHANDLE...FAR SOUTHEAST AL...SOUTHERN GA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 070620Z - 071220Z

SUMMARY...HIGHLY FOCUSED AREAS OF HEAVY SHOWERS AND THUNDERSTORMS
WILL CONTINUE TO BE A CONCERN OVER THE NEXT SEVERAL HOURS.
ADDITIONAL FLASH FLOODING CONCERNS ARE EXPECTED.

DISCUSSION...LATEST EXPERIMENTAL GOES-16 WV IMAGERY SHOWS A RATHER
BROAD SOUTHERN STREAM MID LEVEL TROUGH MOVING SLOWLY EAST ACROSS
THE CENTRAL AND NORTHERN GULF OF MEXICO WITH A RATHER COMPACT VORT
CENTER JUST SOUTH OF THE CENTRAL GULF COAST. A SURFACE LOW CENTER
IS SITUATED ALSO JUST SOUTH OF MOBILE BAY. RADAR IMAGERY SHOWS AN
AREA OF PERSISTENT AND HIGHLY CONCENTRATED HEAVY
SHOWERS/THUNDERSTORMS AROUND THE NORTHEAST FLANK OF THE VORT
CENTER IMPACTING SANTA ROSA AND OKALOOSA COUNTIES...WITH A GRADUAL
SLOW DRIFT OFF TO THE EAST.

THERE IS A CORRIDOR OF ENHANCED SURFACE MOISTURE CONVERGENCE
OCCURRING ACROSS THESE AREAS AHEAD OF THE VORT CENTER AND WITH AT
LEAST MODEST INSTABILITY STILL POOLED OUT OVER THE NORTHERN GULF
OF MEXICO ADVANCING NORTH AHEAD OF THE SURFACE LOW CENTER...THERE
WILL BE A PERSISTENCE OF THIS CONVECTION WITH LOCALLY EXTREMELY
HEAVY RAINFALL RATES THAT WILL BE IN THE 2 TO 3 INCH/HR RANGE
GIVEN A HIGHLY EFFICIENT AND DEEP COLUMN OF MOISTURE/HIGH PWATS.
THIS WILL LIKELY MAINTAIN THE THREAT FOR ADDITIONAL FLASH
FLOODING...WITH WALTON...WASHINGTON AND BAY COUNTIES NEXT IN LINE
TO SEE THIS ACTIVITY.

MEANWHILE...SOME ADDITIONAL CONVECTION HAS BEEN ATTEMPTING TO FORM
FARTHER EAST ACROSS THE FL PANHANDLE AND APPROACHING FAR SOUTHERN
GA ALONG A LOW LEVEL CONVERGENCE AXIS/SURFACE TROUGH. THIS
CONVECTION IS EXPECTED TO MAINTAIN ITSELF AND LIFT A BIT FARTHER
NORTH AS THE VORT CENTER MOVES EAST AND INTERACTS WITH THIS
CONVERGENCE ZONE. GIVEN THE VERY MOIST PROFILES HERE AND SLOW
CELL-MOTION COUPLED WITH AT LEAST SOME TRAINING POTENTIAL...THERE
WILL BE CONCERNS FOR LOCALLY ENHANCED RAINFALL TOTALS HERE TOO AND
POSSIBLE RUNOFF PROBLEMS.

EXPECT POCKETS OF AS MUCH AS AN ADDITIONAL 3 TO 5+ INCHES OF RAIN
NEAR AND TO THE NORTHEAST OF THE VORT CENTER AS IT TRAVERSES ALONG
THE COAST OF THE FL PANHANDLE THROUGH THE EARLY MORNING HOURS.

ORRISON

ATTN...WFO...CHS...FFC...JAX...MOB...TAE...

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

LAT...LON   32018284 31608161 30888146 30538155 30188212
            30018294 30038397 29998445 29768515 30038563
            30308669 30388718 30698741 30958726 31118651
            31198594 31438526 31968404