MESOSCALE PRECIPITATION DISCUSSION 0077
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 AM EDT WED MAY 28 2014
 
AREAS AFFECTED...SOUTHEAST TX/LA/WESTERN MS... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 280658Z - 281128Z
 
SUMMARY...CONVECTION HAS FINALLY BECOME BETTER ORGANIZED ACROSS
SOUTH-CENTRAL LA. A NUMBER OF MESOSCALE MODELS HIGHLIGHT THIS
REGION FOR VERY HEAVY RAINFALL IN THE 06-12Z TIMEFRAME. WITH THAT
IN MIND...FLASH FLOODING WILL BE POSSIBLE...PARTICULARLY IF THE
CURRENT RADAR/SATELLITE TRENDS CONTINUE.


DISCUSSION...A MID/UPPER LEVEL LOW WAS SEEN SPINNING ACROSS
EXTREME NORTHEASTERN TX WITH AN ENHANCED MOISTURE PLUME SURGING
INTO LA. 00Z RAOBS ACROSS THE LOWER MS VALLEY/CENTRAL GULF COAST
ALONG WITH 04Z RAP SOUNDINGS SHOW A MOISTURE RICH AIR MASS IN
PLACE WITH PWATS RANGING FROM 1.75 TO 2.00 INCHES. MUCH OF THE
REGION HAS GENERALLY RECOVERED FROM THE PREVIOUS DAYS CONVECTION
AS SUFFICIENT INSTABILITY IS NOTED ALONG THE IMMEDIATE COASTLINE.
THE ATMOSPHERE IS EXPECTED TO BE UNCAPPED FOR THE NEXT SEVERAL
HOURS WHICH SHOULD CONTINUE TO PROMOTE AN ACTIVE PERIOD OF
CONVECTION. THE PAST FEW SCANS ON SATELLITE SHOWED RAPIDLY COOLING
CLOUD TOPS FROM LAFAYETTE LA UP TOWARD NATCHEZ MS. THE GUIDANCE
DEPICT A NUMBER OF MID-LEVEL IMPULSES SWINGING AROUND THE CLOSED
LOW TOWARD WEST-CENTRAL LA WHICH SHOULD CONTINUE TO INCREASE THE
COVERAGE OF CONVECTION DURING THE NEXT COUPLE OF HOURS. THE 03Z
HRRR AND THE 00Z PARALLEL HRW-ARW SHOW AN AXIS OF 2 TO 4 INCHES OF
RAINFALL THROUGH 12Z IN THE VICINITY OF WHERE THE CONVECTION HAS
BEGUN TO BLOSSOM. THESE MODELS HAVE BEEN THE CLOSEST AT RESOLVING
THE ONGOING CONVECTION SO SUCH A SOLUTION SEEMS TO BE WITHIN THE
REALM OF POSSIBILITIES. WHILE WIDESPREAD FLASH FLOODING IS NOT
EXPECTED PER THE HIGHER END FFG VALUES...A MORE LOCALIZED THREAT
WILL BE POSSIBLE GIVEN THE AFOREMENTIONED IR SATELLITE TRENDS.

RUBIN-OSTER

ATTN...WFO...JAN...LIX...LCH...SHV...

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

LAT...LON   31059416 31469283 32229160 32309092 32089048 31719027
            31129009 30639026 30269072 29979135 29879228 29979341
            30339421 31059416