MESOSCALE PRECIPITATION DISCUSSION 0494...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
640 PM EDT SUN JUL 16 2017

CORRECTED FOR TYPO IN HEADER

AREAS AFFECTED...CNTRL GA TO CNTRL SC

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

VALID 162228Z - 170230Z

SUMMARY...SCATTERED AREAS OF FLASH FLOODING WILL BE POSSIBLE OVER
THE NEXT 4 HOURS OR SO FROM CNTRL GA INTO CNTRL SC. THE POTENTIAL
EXISTS FOR 3-5 INCH TOTALS IN A 1-2 HR PERIOD.

DISCUSSION...A RICH PRECIPITABLE WATER ENVIRONMENT EXISTED SOUTH
OF A SLOW MOVING FRONT ANALYZED FROM THE SERN VA COAST TO FAR NRN
GA/AL AT 22Z. RECENT GPS SITE MEASUREMENTS OF PRECIPITABLE WATER
HAVE SHOWN MAXIMUM VALUES RANGING FROM 2.0 TO 2.2 INCHES EXTENDING
FROM CNTRL SC/GA TO THE EAST COAST. A WEAK LOW-MID LEVEL
CIRCULATION WAS NOTED ON VISIBLE IMAGERY NEAR MLJ AT 22Z...MOVING
TOWARD THE ENE...AND WAS CONNECTED TO SLIGHTLY STRONGER 700-850 MB
WINDS ON ITS SOUTHEAST SIDE...HELPING TO CONTINUE ADVECTING HIGH
PWAT AIR INLAND. MLCAPE VALUES OF 1000-2000 J/KG...PER SPC
MESOANALYSES...WERE IN AN AREA WHICH HAS NOT YET SEEN CONVECTION
TODAY...EXTENDING ACROSS MUCH OF CNTRL GA TO SC. A WEAK BUT
POTENTIALLY SIGNIFICANT 250 MB JET MAX WAS ALSO OBSERVED VIA GOES
HD WINDS AND RAP ANALYSES ABOVE THE ERN SLOPES OF THE SRN AND
CNTRL APPALACHIANS...WHICH MAY ACT TO ENHANCE LIFT IN THE NEAR
TERM WITHIN THE ENTRANCE REGION.

STEERING FLOW REMAINS WEAK AND WHILE CONVECTION HAS BEEN LARGELY
OUTFLOW DOMINANT DURING THE LATE AFTERNOON...SHORT LIVED
CONVECTION HAS ALREADY BEEN RESPONSIBLE FOR RAINFALL RATES NEAR 3
IN/HR IN MCINTOSH COUNTY EARLIER TODAY.

DEVELOPMENT AND SLOW MOVEMENT OF STORMS IS EXPECTED TO PICK UP
FROM CNTRL GA INTO SC FOLLOWED BY CONVERGING OUTFLOW BOUNDARIES
WHICH WHEN COMBINED WITH CELL MERGERS MAY ACT TO ENHANCE THE FLASH
FLOOD THREAT OVER THE NEXT 2-4 HOURS FROM CNTRL GA INTO CNTRL SC.
A QUICK 3-5 INCHES WILL BE POSSIBLE WHICH COULD RESULT IN
EXCESSIVE RUNOFF.

OTTO

ATTN...WFO...CAE...CHS...FFC...GSP...

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

LAT...LON   34698199 34388054 33628023 32788093 32138212
            32218287 32788372 33548395 34348334