MESOSCALE PRECIPITATION DISCUSSION 0300
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1250 PM EDT FRI JUN 03 2016
 
AREAS AFFECTED...EASTERN TX...CENTRAL/WESTERN LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 031640Z - 032100Z
 
SUMMARY...ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH
HEAVY RAINFALL RATES THIS AFTERNOON WHICH IS EXPECTED TO PRODUCE
MORE POTENTIAL FOR FLASH FLOODING.

DISCUSSION...A DEEP LAYER SOUTHERLY FETCH OF TROPICAL MOISTURE
CONTINUES TO FEED NORTH IN ACROSS THE WESTERN GULF COAST STATES
AND THE LOWER MS VALLEY. THIS IS ALL OUT AHEAD OF A DEEP CLOSED
LOW OVER CENTRAL TX WHICH IS ESSENTIALLY STATIONARY AT THIS TIME.

THE STRONGEST FOCUS THIS AFTERNOON FOR HEAVY SHOWERS AND
THUNDERSTORMS WILL BE MAINLY ACROSS CENTRAL/SOUTHERN LA AND
WRAPPING A BIT BACK TO THE NORTHWEST TOWARD NORTHWEST INTO FAR
EASTERN TX WHERE CONFLUENT LOW LEVEL FLOW WILL BE IN PLACE AS
SHORTWAVE ENERGY EJECTING GRADUALLY NORTHEAST AROUND THE EASTERN
FLANK OF THE UPPER LOW CROSSES THIS REGION. THE ENERGY WILL ALSO
BE INTERACTING WITH THE AFOREMENTIONED BAND OF DEEP MOISTURE...AND
GIVEN THE INCREASE IN SURFACE-BASED INSTABILITY VIA SOLAR
INSOLATION...THE OVERALL CONVECTIVE POTENTIAL SHOULD TEND TO
EXPAND A BIT IN COVERAGE.

PWATS ARE CLOSE TO 2 INCHES ACROSS THE LOWER MS VALLEY WITH SBCAPE
VALUES OVER SOUTHERN LA NOSING UP BETWEEN 2000 AND 3000 J/KG. THE
COMBINATION OF BOTH WILL RESULT IN VERY RAINFALL RATES THAT ARE
EXPECTED TO APPROACH 2.5 INCHES/HR. THERE HAVE ALREADY BEEN SOME
OVERSHOOTING TOPS WITHIN THE ONGOING CONVECTIVE BAND THAT HAS
IMPACTED SOUTHEAST LA TODAY...AND ADDITIONAL OVERSHOOTING TOPS ARE
EXPECTED WHICH COULD ENHANCE THE RAINFALL RATES FURTHER.

THE HIRES GUIDANCE SEEMS TO BE UNDERPLAYING THE CONVECTIVE THREAT
ACROSS CENTRAL/SOUTHERN LA BASED ON THE RADAR TRENDS...AND THE
DEGREE OF INSTABILITY POOLING IN OFF THE GULF OF MEXICO. EXPECT
RAINFALL AMOUNTS THROUGH 21Z TO BE AS HIGH AS 3 TO 6 INCHES WITHIN
THE MAIN AXIS OF CONVECTION CURRENTLY SHIFTING GRADUALLY EAST
ACROSS THE STATE. GIVEN SOME OF THE HEAVY RAINFALL SEEN
LATELY...EXPECT RUNOFF PROBLEMS AND SOME FLASH FLOODING TO BE
POSSIBLE THIS AFTERNOON.

ORRISON

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

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

LAT...LON   32929388 32589269 31039152 29449116 29039189 
            29319259 30099301 30359319 30799376 31199462 
            31649514 32229524 32679486