MESOSCALE PRECIPITATION DISCUSSION 0287
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
547 PM EDT TUE MAY 30 2017

AREAS AFFECTED...SOUTHEAST LA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 302200Z - 310200Z

SUMMARY...SLOW MOVING CONVECTION COMING ASHORE OVER SOUTHEAST LA
THIS EVENING COULD RESULT IN FLOODING CONCERNS.

DISCUSSION...CONVECTION CONTINUES TO MOVE ONSHORE ACROSS SOUTHEAST
LA...PER REGIONAL RADARS. NORTH OF THE CONVECTION...OUTFLOW FROM
EARLIER STORMS HAS PRODUCED A MORE STABLE ENVIRONMENT OVER MUCH OF
SOUTHERN LA (AS CIN HAS INCREASED WITH TIME). THE BEST INSTABILITY
(WITH MLCAPE VALUES GENERALLY BETWEEN 500-1000 J/KG) REMAINS OVER
FAR SOUTHEAST LA AND JUST OFFSHORE.

THE COLUMN REMAINS MOIST...AS A 20 TO 25 KT LOW LEVEL SOUTHEAST
INFLOW CONTINUES TO POUR 2.00+ INCH PRECIPITABLE WATER AIR INTO
SOUTHEAST LA. THE CONVECTION IS EXPECTED TO FOLLOW THE BEST
INSTABILITY AND MOISTURE AS IT TRACKS FROM THE GULF OF MEXICO
ACROSS SOUTHEAST LA.

THE LATEST HRRR SEEMED TO HAVE THE BEST HANDLE ON THE POSITION OF
THE CONVECTION... AND THAT SOLUTION TAKES THE CONVECTION OVER THE
LA GULF WATERS ACROSS SOUTHEAST LA BEFORE WEAKENING AFTER 02Z. THE
LATEST HRRR SHOWED THE POTENTIAL FOR AREAS OF 2.00 TO 4.00 INCHES
OF RAINFALL ACROSS SOUTHEAST LA. THE MOISTURE AND INSTABILITY
SHOULD BE SUFFICIENT TO SUPPORT THESE RAINFALL AMOUNTS. FLOODING
IS POSSIBLE BEFORE THE BEST CONVECTION MOVES OFFSHORE LATER THIS
EVENING.

HAYES

ATTN...WFO...LIX...

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

LAT...LON   30269006 30269003 30218977 30118950 29978928
            29788915 29568906 29378904 29188908 29058922
            29028946 29028973 29038999 29059019 29149050
            29229077 29319087 29469094 29649097 29889087
            30259033