MESOSCALE PRECIPITATION DISCUSSION 0386
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
704 PM EDT FRI JUN 23 2017

AREAS AFFECTED...CENTRAL & SOUTHERN AL...COASTAL MS

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

VALID 232250Z - 240300Z

SUMMARY...RECENT ENHANCEMENT OF CONVECTIVE LINE THROUGH SATURATED
AREAS LIKELY TO PRODUCE FLASH FLOODING.

DISCUSSION...GOES-E/RADAR MOSAIC SHOWS A RECENT UPTICK IN
CONVECTION ALONG THE TRAILING SOUTHERN BAND OF THE REMNANTS OF TC
CINDY. THIS APPEARS TO BE ASSOCIATED WHEN THE BAND SHIFTING INTO
THE LINGERING MOISTURE ASSOCIATED WITH THE DYING WARM CONVEYOR
BELT.  CIRA LAYERED TPW DELINEATES THIS INCREASED MOISTURE FROM
MOBILE BAY TO THE TN/NC BORDER AND NORTHEAST.  THIS IS LEADING TO
TPW OVER 2.0".  ADDITIONALLY RAP ANALYSIS SHOWS MODEST INSTABILITY
TO ALLOW FOR STRONGER UPDRAFTS AS WELL.  LESS EVAPORATIVE DRYING
HAS ALLOWED FOR THE UPDRAFTS TO BE LESS OUTFLOW DOMINANT FOR A
SHORT TIME AS WELL.  THIS IS PARTICULARLY THE CASE TOWARD COASTAL
MS AND S AL WHERE MEAN CLOUD BEARING FLOW IS WEAKER TOO ALLOWING
FOR LONGER HEAVY RAINFALL DURATION TO COMPOUND.  GIVEN FFG ARE NOT
REALISTIC HAVING REBOUNDED TOO QUICK...FLASH FLOODING IS LIKELY
ACROSS THESE AREAS WHERE 1-3" OF RAIN ARE EXPECTED RELATIVELY
QUICKLY. AS THE LINE ADVANCES FURTHER EASTWARD INTO SE AL...DRY
AIR FROM THE NORTHERN GULF/TUTT TO THE SOUTH SHOULD ONCE AGAIN MIX
THROUGH THE CELLS AND REINVIGORATE FORWARD PROPAGATION/OUTFLOW
BOUNDARY.  STILL FLASH FLOODING IS POSSIBLE GIVEN THE GROUNDS ARE
SATURATED TOO WITH 1-2" TOTALS REMAINING POSSIBLE THROUGH THE LATE
EVENING/EARLY OVERNIGHT HOURS.

GALLINA

ATTN...WFO...BMX...JAN...LIX...MOB...

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

LAT...LON   33798554 33248528 32248540 31348663 30258786
            30318864 30288925 30688973 32238813 33488603