MESOSCALE PRECIPITATION DISCUSSION 0112
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
719 PM EDT MON APR 11 2016
AREAS AFFECTED...S MISSISSIPPI...SW ALABAMA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 112320Z - 120400Z
SUMMARY...HVY RAINFALL ASSOCIATED WITH APPROACHING SQUALL LINE.
DISCUSSION...VIS/IR SATL AND RADAR MOSAIC SHOW WELL DEFINED
MCS/SQUALL LINE MOVING SEWARD ACROSS CENTRAL MS AND EXTENDING UP
TOWARD BHM. BEST INSTABILITY AND MST FLUX/INFLOW TO THE COMPLEX
IS ENHANCED ON THE SW EDGE TOWARD JAN ATTM WITH IR TOPS TO -75C
AND WITH MST AVAILABLE TO 1.75" AND SBCAPES IN THE 500-1000 J/KG
RANGE THROUGH THE LATE EVENING...CELLS WILL CONTINUE TO BE QUITE
EFFICIENT WITH RATES OF 1.5-2.0"/HR WITH NEARLY 1.5" IN LESS THAN
20 MINUTES IN PART FOLLOWED BY A BROAD SHIELD OF MODERATE
PRECIPITATION BEHIND SUPPORTED BY THE ISENTROPIC ASCENT FROM SWLY
FLOW ACROSS THE NW-SE OUTFLOW BOUNDARY ALONG THE WESTERN EDGE OF
THE MCS ITSELF. CANNOT RULE OUT ISOLATED CELLS FORMING AHEAD OF
THE SQUALL LINE AS IT MOVES SOUTH...AND MERGING INCREASING THE
SHORT TERM FLASH FLOOD THREAT EVEN WITHIN INCREASINGLY HIGHER
GUIDANCE VALUES NEARER THE COASTAL COUNTIES. THE THREAT OF MOST
EXTREME RATES REDUCES FURTHER EAST IN S AL...AWAY FROM INSTABILITY
POOL OVER SE LA/SW MS AND BEST ASCENT/FORCING AS WELL...BUT
FLOODING THREAT IS NOT NEGLIABLE.
GALLINA
ATTN...WFO...BMX...HUN...JAN...MOB...
ATTN...RFC...LMRFC...SERFC...
LAT...LON 34138731 33378612 32218595 31678670 31188808
31198921 31729018 32459044 32868980 33458880
Last Updated: 719 PM EDT MON APR 11 2016