MESOSCALE PRECIPITATION DISCUSSION 0079
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1252 PM EST FRI MAR 11 2016
 
AREAS AFFECTED...SOUTHEAST LA...MS...PORTIONS OF AL INTO THE
WESTERN FL PANHANDLE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 111800Z - 112200Z
 
SUMMARY...DEEP MOISTURE AND INSTABILITY AHEAD OF A WEAKENING COLD
POOL OVER PORTIONS OF SOUTHEAST MS INTO SOUTHWEST AL AND THE
WESTERN FL PANHANDLE WILL MAINTAIN A FLASH FLOOD THREAT INTO THE
LATE AFTERNOON HOURS.

DISCUSSION...THE MAIN FOCUS FOR FLASH FLOODING IS EXPECTED TO BE
FOCUSED ON THE WEAKENING COLD POOL AHEAD OF A SQUALL LINE CROSSING
PORTIONS OF SOUTHEAST MS INTO SOUTHWEST AL AND THE WESTERN FL
PANHANDLE. THE LATEST BLENDED TPW IMAGES SHOWED PRECIPITABLE WATER
VALUES NEAR 2.00 INCHES FEEDING INTO THIS AREA ON A 20 TO 25 KNOT
LOW LEVEL SOUTHERLY FLOW. INSTABILITY HAS BECOME MOSTLY ELEVATED
ACROSS MS/AL...AS THE BEST MUCAPE VALUES (BETWEEN 500 AND 1000
J/KG) CONTINUE TO REMAIN OVER THE NORTHERN GULF OF MEXICO. 

KMOB RADAR SHOWED HOURLY RAINFALL RATES LOWERING TO ABOUT 1.50
INCHES OVER SOUTHWEST AL...AND THE LATEST MRMS PRECIPITATION RATES
PRODUCT SHOWED RAINFALL RATES BETWEEN 1.50 AND 2.00 INCHES.
OVERALL...THE SYNOPTIC SETUP CHANGES LITTLE THROUGH 22Z ACROSS THE
GULF COAST STATES EAST OF THE STRONG CLOSED UPPER LOW...WITH LOW
LEVEL CONVERGENCE AND FAVORABLE UPPER LEVEL DIFFLUENCE IN PLACE.

MOST OF THE AVAILABLE HIGH RESOLUTION GUIDANCE SUGGESTS THAT THE
LOW LEVEL CONVERGENCE SLOWLY BECOMES DISRUPTED...AS THE LOW LEVEL
FLOW CONTINUES TO WEAKEN. THERE IS A STRONG SIGNAL FOR A FLASH
FLOOD THREAT REMAINING NEAR THE OUTFLOW FROM THE CURRENT
CONVECTION OVER SOUTHWEST AL... WHICH DRIFTS INTO THE WESTERN FL
PANHANDLE. IN THIS AREA...ADDITIONAL RAINFALL AMOUNTS OF 2 OR 3
INCHES ARE POSSIBLE...ESPECIALLY WHERE ANY TRAINING OCCURS.

FURTHER WEST ACROSS PORTIONS OF SOUTHEAST LA INTO SOUTHERN MS...AN
AREA OF MODERATE TO HEAVY RAINFALL STREAMING NORTH FROM THE GULF
OF MEXICO COULD PRODUCE ADDITIONAL RAINFALL NEAR AN INCH. THE
ADDITIONAL RAINFALL COULD EXACERBATE FLOODING THROUGH LATE
AFTERNOON. 

HAYES

ATTN...WFO...BMX...JAN...LIX...MOB...

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

LAT...LON   33168925 32988810 32048737 30738721 29568783 
            29168830 29008924 29078930 29559014 30659031 
            31849027 32858990