MESOSCALE PRECIPITATION DISCUSSION 0102
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
154 PM EDT WED APR 05 2017

AREAS AFFECTED...SOUTHEAST AL, CENTRAL GA, CENTRAL & EASTERN SC

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

VALID 051754Z - 052259Z

SUMMARY...THUNDERSTORMS WITH HEAVY RAIN CONTINUE TO BLOSSOM ACROSS
THE SOUTHEAST.  HOURLY RAIN RATES TO 2", WITH ADDITIONAL AMOUNTS
OF 3-5", COULD LEAD TO FLASH FLOODING 

DISCUSSION...CLOUD TOPS ARE COOLING/ EXPANDING WITH CONVECTION
MOVING THROUGH GA AND SC.  HEAVY RAIN CORES ARE SLOWLY INCREASING
IN NUMBER ACROSS THE REGION, PER RADAR IMAGERY, DUE TO TRAINING
BANDS.  A TORNADIC CELL APPEARS TO HAVE SPAWNED A MESOSCALE WAVE
NEAR PLAINS GA, WITH A TRAILING BOUNDARY DIVIDING SUNNY AREAS IN
THE WARM SECTOR OF AN OCCLUDED CYCLONE WITH CLOUDY AREAS FARTHER
WEST.  IN THE WARM SECTOR, MLCAPES OF 2000-3000 J/KG LIE ACROSS
NORTH FL AND SOUTHERN GA.  INFLOW AT 850 HPA OF 30-50 KTS IS NOTED
IN REGIONAL VAD WIND PROFILES.  BEST GUESS AS TO THE PRECIPITABLE
WATER VALUES IN THE REGION IS 1.5-1.75".

WHILE THE MAIN HEAVY RAIN RISK APPEARS TO LIE NORTHEAST OF THE
INSTABILITY POOL ACROSS EASTERN GA AND SC, A TRAILING BAND OF
THUNDERSTORMS ACROSS EXTREME SOUTHEAST AL AND SOUTHWEST GA HAS
BEEN LEADING TO HEAVY RAINFALL AS WELL.  THE AVAILABLE MOISTURE
AND INSTABILITY SUPPORT HOURLY RAIN RATES TO 2", WITH LOCAL
AMOUNTS OF 3-5" ANTICIPATED.  MOST OF THE GUIDANCE THAT
INITIALIZED GPS PRECIPITABLE WATER VALUES WAS USELESS IN THIS
REGION; A SOUTHWARD ADJUSTED 12Z GFS/12Z CANADIAN REGION MODEL
APPEARS BEST HERE PATTERN-WISE.

ROTH

ATTN...WFO...BMX...CAE...CHS...FFC...GSP...ILM...JAX...TAE...

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

LAT...LON   34278308 34178074 33887878 33767864 33487898
            33137914 32857946 32468011 32148104 31748220
            31488326 31158465 31068493 31078539 31258572
            31928557 32638485 33618525 34248477