MESOSCALE PRECIPITATION DISCUSSION 0311
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
209 PM EDT SAT JUN 04 2016
 
AREAS AFFECTED...CENTRAL AND SOUTHERN LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 041800Z - 050000Z
 
SUMMARY...HEAVY RAINS WILL OVERSPREAD CENTRAL LA AND CONTINUE
ACROSS SOUTHERN LA THIS AFTERNOON. VERY INTENSE RAINFALL RATES OF
OVER 2.5 INCHES/HR WILL PROMOTE ADDITIONAL FLASH FLOODING.

DISCUSSION...INTENSE SHOWERS AND THUNDERSTORMS CONTINUE TO EVOLVE
OVER SOUTHERN LA...WITH SMALL TRAINING BANDS OF CONVECTION NOTED
OUT AHEAD OF LONG-LIVED MCS OVER THE NORTHWEST GULF OF MEXICO. A
WELL-DEFINED MCV IS NOW SEEN WITH THIS SYSTEM. 

SEMI-UNIDIRECTIONAL FLOW AS SEEN IN THE 12Z LCH SOUNDING HAS
CREATED AN ENVIRONMENT CONDUCIVE TO TRAINING WHILE SATURATED
PROFILES REFLECTIVE OF TALL SKINNY CAPE AND HIGH PWATS HAVE SET UP
A HIGHLY EFFICIENT RAINFALL ENVIRONMENT. THIS ENVIRONMENT SHOULD
REMAIN IN PLACE THIS AFTERNOON WITH A PERSISTENCE OF DEEP LAYER
SOUTHERLY FLOW OVER THE REGION EAST OF A LARGER SCALE UPPER LOW
OVER SOUTHEAST TX.

THE STRONG INSTABILITY THAT HAS BEEN POOLED AHEAD OVER THE
NORTHWEST GULF OF MEXICO CONTINUES TO FOCUS FARTHER NORTH ACROSS
SOUTHERN LA AND OVER THE NEXT FEW HOURS...CONVECTION WILL LIFT
FARTHER NORTH ACROSS CENTRAL LA. MERGING CLUSTERS OF CONVECTION
AND TRAINING OF CELLS WILL CONTINUE TO FOCUS HEAVY RAINFALL...WITH
RATES OVER 2.5 INCHES/HR...AND ADDITIONAL AMOUNTS THROUGH
LATE-AFTERNOON OF 4 TO 7 INCHES...ESPECIALLY OVER SOUTHERN LA.
RECENT HRRR OUTPUT FAVORS LOCALLY HEAVIER AMOUNTS OVER THIS...AND
THUS GIVEN THE RECENT RAINFALL AND SATURATING SOIL...ADDITIONAL
FLASH FLOODING IS EXPECTED.

ORRISON

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

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

LAT...LON   31889319 31649208 30699113 29759062 29279074 
            29169123 29519229 30089270 30649348 31299375