MESOSCALE PRECIPITATION DISCUSSION 0016
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
536 AM EDT MON APR 07 2014
 
AREAS AFFECTED...SERN LA...CNTRL/SERN MS...AL...NWRN GA...EXTREME
WRN FL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 070925Z - 071500Z
 
SUMMARY...LIFE-THREATENING FLASH FLOODING IS EXPECTED ACROSS THE
GULF COAST STATES THIS MORNING AS STRONG LINEAR BANDS OF TRAINING
CONVECTION AND CELL-MERGERS CONTINUE.

DISCUSSION...THE LATEST IR/WV SATELLITE IMAGERY CONTINUES TO SHOW
VERY DIFFLUENT FLOW ALOFT OVER THE GULF COAST STATES OUT AHEAD OF
A STRONG SRN STREAM UPPER TROUGH MOVING INTO THE LOWER AND MIDDLE
MS VLY REGION. A VERY WELL-DEFINED SUBTROPICAL JET COUPLED WITH A
PERSISTENTLY STRONG LOW LVL JET ON THE ORDER OF 50 TO 60 KTS IN
OFF THE GULF OF MEXICO AHEAD OF MULTIPLE WAVES OF SFC LOW PRESSURE
IS CONTRIBUTING TO PWATS ON THE ORDER OF 1.7 TO 1.9 INCHES ACROSS
SERN LA...CNTRL/SRN MS AND CNTRL/SRN AL AS PER LATEST GOES-SOUNDER
AND GPS-DERIVED DATA. A WARM FRONT CONTINUES TO GRADUALLY LIFT NWD
AND GIVEN VERY STRONG UPPER LVL JET DYNAMICS/DIFFLUENT FLOW ALOFT
IS CONTRIBUTING TO STRONG AND SUSTAINABLE DEEP LAYER ASCENT. THIS
COUPLED WITH A WELL-DEFINED FEED OF LOW LVL INSTABILITY OFF THE
GULF OF MEXICO WHERE MUCAPE VALUES OF 2000 J/KG ARE NOTED WILL
CONTINUE TO FOSTER ORGANIZED AND COLD-TOPPED CONVECTION WITH
LINEAR BANDING AND TRAINING ALONG WITH SEVERAL AREAS OF
CELL-MERGERS. NUMEROUS OVERSHOOTING DETECTIONS ARE NOTED IN LATEST
IR IMAGES OVER CNTRL AL NEAR A NUMBER OF CELL-MERGERS. GIVEN THE
NEARLY PARALLEL LOW/MID LVL FLOW RELATIVE TO THE ACTIVE AREAS OF
DEEP CONVECTION AND FRONTAL ZONE...A SIGNIFICANT THREAT OF
TRAINING CONVECTION WILL PERSIST AT LEAST UNTIL MID-MORNING WHEN A
COLD FRONT SHOULD BEGIN GRADUALLY SHIFTING THE CONVECTION FARTHER
EAST. 

THE LATEST GUIDANCE SUPPORTS THE IDEA OF CONTINUED SW/NE ORIENTED
CONVECTION AND AFOREMENTIONED CONCERN FOR TRAINING AND
CELL-MERGERS. RAINFALL RATES HAVE BEEN REPORTED TO BE OVER 2
INCHES/HR...AND EXPECT NUMEROUS STORM TOTALS OF 4 TO 8 INCHES WITH
SOME AREAS POSSIBLY EXCEEDING 10 INCHES. LIFE-THREATENING FLASH
FLOODING IS EXPECTED AS A RESULT. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...GSP...MRX...FFC...TAE...BMX...HUN...MOB...JAN...
LIX...

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

LAT...LON   32368923 31609000 30759051 29929003 29698880 30088780
            30958650 32558468 33798345 34668355 34978438 35078543
            34708661 33548804 32368923