MESOSCALE PRECIPITATION DISCUSSION 0032
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1056 PM EDT MON APR 28 2014
 
AREAS AFFECTED...EASTERN LA/MS/AL/CENTRAL TN/NORTHWESTERN GA... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 290241Z - 290611Z
 
SUMMARY...FLASH FLOODING CONTINUES TO AFFECT AREAS OF
SOUTH-CENTRAL MS ALONG WITH NORTHERN AL. NATIONAL WEATHER SERVICE
LOCAL STORM REPORTS INDICATED NUMEROUS ROAD CLOSURES DUE TO
UNPASSABLE/FLOODED ROADS. THE FORECAST STORM MOTIONS INDICATE
BACKBUILDING/TRAINING CONVECTION WILL BE FAVORED INTO THE
OVERNIGHT HOURS...PARTICUARLY AT THE FOCAL POINT OF CONVECTIVE
DEVELOPMENT ACROSS FAR EAST-CENTRAL LA/WESTERN MS.


DISCUSSION...A POWERFUL MID-LEVEL CYCLONE SPINNING ACROSS THE
CENTRAL PLAINS HAS HELPED BRING WELL ABOVE NORMAL MOISTURE INTO
THE DEEP SOUTH WITH PWAT ANOMALIES APPROACHING THE 95TH TO 99TH
PERCENTILES ACROSS THE TN RIVER VALLEY. THE COMBINATION OF
PERSISTENT LOW-LEVEL INFLOW ALONG THE CORRIDOR OF BEST INSTABILITY
WITH A STRONG DIFFLUENT JET STRUCTURE ALOFT WILL AID IN THE
DEVELOPMENT OF MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS.
ADDITIONAL MID-LEVEL JET ENERGY ROUNDING THE BASE OF THE UPPER
TROF WILL PROVIDE ADDITIONAL ASCENT TO SUSTAIN LOCAL UPDRAFTS.
BASED ON THE LATEST RAP ANALYSIS...SOME OF THE ATMOSPHERE HAS
STABILIZED AS CIN VALUES HAVE BEEN ON THE INCREASE.
HOWEVER...REGIONS DOWNSTREAM ACROSS SOUTHERN/CENTRAL MS/AL REMAIN
UNCAPPED WITH MUCAPE VALUES RANGING FROM 2000 TO 3000 J/KG. THE
LOW-TO-MID LEVEL FLOW GENERALLY PARALLELING THE ONGOING CONVECTION
SHOULD SUPPORT BACKBUILDING AND REPEAT CONVECTION THROUGH AT LEAST
06Z.

THE AVAILABLE HIGH-RESOLUTION/CONVECTION-ALLOWING MODELS SUGGEST
THE POSSIBILITY OF ANOTHER 2 TO 4 INCHES OF RAINFALL WITH RATES
EXCEEDING 2 INCHES PER HOUR AT TIMES. BASED ON THE LATEST RADAR
ESTIMATES...SOME LOCATIONS HAVE ALREADY RECEIVED 3 TO 5 INCHES OF
RAINFALL DURING THE PAST 6 HOURS. THE LOOMING THREAT FOR
ADDITIONAL HEAVY PRECIPITATION WILL EXASCERBATE THE FLASH FLOOD
THREAT ACROSS THE REGION.



RUBIN-OSTER

ATTN...WFO...MRX...FFC...LMK...OHX...BMX...HUN...MOB...MEG...
JAN...LIX...LCH...SHV...

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

LAT...LON   36638600 36488519 36098485 35338461 34488486 33478575
            31818699 31098785 30668886 30389037 30519194 30969240
            31379227 31879117 32279036 32588991 33358925 33978892
            35218830 36088757 36558707 36638600