MESOSCALE PRECIPITATION DISCUSSION 0021
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
546 PM EDT MON APR 14 2014
 
AREAS AFFECTED...SOUTHEAST LA...SOUTHERN MS...SOUTHERN
AL...EXTREME WESTERN FL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 142135Z - 150145Z
 
SUMMARY...CONVECTION OVER SOUTHEAST LA SHOULD INTENSIFY FURTHER
AND EXPAND EAST THE NEXT FEW HOURS. GIVEN SOME POTENTIAL FOR
TRAINING AND WITH VERY HEAVY RAINFALL RATES...SOME FLASH FLOODING
WILL BE POSSIBLE.

DISCUSSION...THE LATEST IR SAT IMAGERY SHOWS CLOUD TOPS ASSOCIATED
WITH ALREADY ACTIVE CONVECTION OVER SRN AND SERN LA CONTINUING TO
COOL. THE CONVECTION IS BEING FOSTERED BY A VERY MOIST AND
MODERATELY UNSTABLE AIRMASS INTERACTING WITH THE PRESENCE OF AN
OUTFLOW BNDRY THAT WAS LAID DOWN ACROSS PORTIONS OF THE CNTRL GULF
COAST OVER THE LAST SEVERAL HOURS DUE TO ORGANIZED CONVECTION
EARLIER IN THE DAY FARTHER NORTH. IN ADDITION TO THIS...LARGER
SCALE FORCING FOR CONVECTIVE DEVELOPMENT IS BEING ENHANCED BY THE
SRN TAIL OF A SHORTWAVE TROUGH EXITING NEWD OUT ACROSS THE CNTRL
PLAINS. MEANWHILE...A COLD FRONT IS SEEN MOVING RATHER QUICKLY
EASTWARD INTO THE REGION AS WELL AND IS BEGINNING TO MERGE WITH
THE PRE-FRONTAL CONVECTION.

THE LATEST HI-RES MODEL DATA INCLUDING THE 12Z ARW...12Z NMM AND
12Z GEM REGIONAL ALL SUGGEST A PERIOD OF STRONG W/E ORIENTED
CONVECTION SETTING UP FOR THE NEXT SEVERAL HOURS JUST NORTH OF THE
CNTRL GULF COAST AND MOVING GRADUALLY ENEWD WITH TIME. DESPITE
HIGH FFG VALUES ACROSS THIS REGION...THE RAINFALL RATES SHOULD BE
QUITE HIGH AND UP TO AROUND 2 INCHES/HR IF NOT HIGHER. THIS
COUPLED WITH A FAVORABLE SET-UP FOR TRAINING WILL FAVOR SOME
POTENTIAL FOR SHORT-TERM FLASH FLOODING. IN FACT...THE
AFOREMENTIONED MODELS SUPPORT SEVERAL INCHES OF RAIN THROUGH 00Z
AND EVEN AFTER 00Z LOCALLY. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...MOB...JAN...LIX...LCH...

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

LAT...LON   30649147 31209055 31718904 31918805 32008718 31658651
            31158660 30718712 30138825 29868907 29688988 29549128
            29579172 29909216 30289197 30649147