MESOSCALE PRECIPITATION DISCUSSION 0139
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
844 AM EDT WED MAY 27 2015
 
AREAS AFFECTED...LA...MS...TN...AL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 271244Z - 271844Z
 
SUMMARY...FLASH FLOODING WILL BECOME INCREASINGLY POSSIBLE ACROSS
PORTIONS OF LA/MS/TN/AL THROUGH EARLY AFTERNOON.

DISCUSSION...REGIONAL ANALYSIS SHOWS A SQUALL LINE CROSSING LA AND
APPROACHING 2 RESIDUAL BOUNDARIES...1 ACROSS NORTH CENTRAL
MS...AND ANOTHER DRAPED ALONG THE LA COAST...BOTH WITH SUBTLE
THERMAL AND MOISTURE GRADIENTS. 12Z RAOBS AT LIX AND JAN SHOW VERY
MOIST CONDITIONS EXTENDING TO ABOUT 600 MB...MIXED LAYER CAPES OF
1500-2300 J/KG...AND MEAN CLOUD LAYER WINDS OF 15 TO 20 KNOTS.

GIVEN ANOTHER 3 TO 6 HOURS OF INSOLATION...CAPE VALUES SHOULD
CONTINUE TO RISE ALONG WITH DIMINISHING CIN SUCH THAT WIDESPREAD
CONVECTION SHOULD EXPAND AHEAD OF THE SQUALL LINE AS IT EVENTUALLY
MERGES WITH THE OTHER BOUNDARIES 16-19Z...WITH THE INTENSITY AND
DEPTH OF CONVECTION ALONG WITH THE WEAK CLOUD LAYER WINDS
SUPPORTING HOURLY RATES OF 2 INCHES PER HOUR. THESE RATES ARE
CAPABLE OF EXCEEDING LOCAL FFG VALUES...ESPECIALLY ACROSS CENTRAL
MS INTO WESTERN TN...WHERE THE VALUES ARE SLIGHTLY LOWER.

JAMES

ATTN...WFO...BMX...HUN...JAN...LCH...LIX...MEG...MOB...OHX...

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

LAT...LON   36028790 34928755 32448882 31208892 30868768 
            30128707 29318718 29108911 29429150 30029261 
            31089237 32649161 34299062 35858926