MESOSCALE PRECIPITATION DISCUSSION 0033
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
212 AM EDT TUE APR 29 2014
 
AREAS AFFECTED...FAR SOUTHEASTERN LA/SOUTHERN MS/AL/WESTERN
GA/WESTERN FL PANHANDLE... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 290611Z - 291011Z
 
SUMMARY...VERY HEAVY RAINFALL CONTINUES TO AFFECT EXTREME SOUTHERN
MS AND INTO SOUTHERN/CENTRAL AL WITH RAINFALL RATES EXCEEDING 2
INCHES PER HOUR. AREAS OF FLASH FLOODING WILL REMAIN LIKELY GIVEN
THE CONTINUAL HEAVY RAINS FALLING ONTO THE SATURATED SOILS.
NUMEROUS REPORTS OF FLOODED/UNPASSABLE ROADS HAVE ALREADY BEEN
NOTED ACROSS THE AFFECTED REGION.


DISCUSSION...DURING THE PAST FEW HOURS...THE CORE OF THE STRONGEST
CONVECTION HAS FOCUSED CLOSER TOWARD THE GULF COAST WHERE THE
BETTER MOISTURE CONVERGENCE HAS BEEN IN PLACE. VERY SLOW STORM
MOTION VECTORS CONTINUE TO SUPPORT TRAINING/BACKBUILDING
CONVECTION...PARTICUARLY ACROSS SOUTHEASTERN MS/SOUTHERN AL. THIS
SYSTEM ALREADY HAS A HISTORY OF DROPPING EXTREMELY HEAVY RAINFALL
WITH AREAS IN THE VICINITY OF HATTIESBURG...MS REPORTING 3 TO 4
INCHES IN THE PAST 3 HOURS. THE IR SATELLITE TRENDS SUPPORT THE
IDEA THAT THE FOCUS WILL BE SOMEWHAT CONFINED CLOSER TO THE
SOUTHERN EXTENT OF MS/AL AND EVENTUALLY INTO THE FAR WESTERN
PANHANDLE OF FL. THE COLDEST CLOUD TOPS AS OF 545Z WERE WITHIN A
SQUALL LINE WITH TEMPERATURES REACHING -80C OR APPROACHING 53000
FEET BASED ON LAPS DATA. THE 05Z RAP ANALYSIS SHOWED THE
ENVIRONMENT FEEDING INTO THE COMPLEX REMAINS UNCAPPED WITH MUCAPE
VALUES NEARING THE 3000 TO 4000 J/KG RANGE. SUCH INSTABILITY
EXISTS DOWNSTREAM ALL THE WAY INTO MUCH OF THE FL PANHANDLE.
OVERALL THE HIGH-RESOLUTION GUIDANCE IS IN FAIR AGREEMENT WITH
DROPPING AT LEAST 2 TO 5 INCHES OF RAINFALL THROUGH 12Z WITH RATES
EXCEEDING 2 INCHES PER HOUR AT TIMES.


RUBIN-OSTER

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

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

LAT...LON   33508474 32668489 31528566 31018602 30258675 29758761
            29708883 30018969 30828986 31658863 32168794 32888744
            34078675 34418606 34128538 33508474