MESOSCALE PRECIPITATION DISCUSSION 0153
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
117 AM EDT SAT APR 30 2016
 
AREAS AFFECTED...EAST TX...NORTHWEST LA...SOUTHERN AR 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 300516Z - 300930Z
 
SUMMARY...THE RISK OF FLASH FLOODING WILL CONTINUE OVER PORTIONS
OF TX/AR/LA GIVEN THE APPROACH OF THUNDERSTORMS  FROM THE WEST AND
CONTINUED INFLOW OF MOISTURE FROM THE SOUTH AHEAD OF THE STORMS.  

DISCUSSION...RADAR SHOWED A LINE OF THUNDERSTORMS CAPABLE OF
PRODUCING HEAVY RAINFALL SHORTLY BEFORE 05Z.  THE ENVIRONMENT
AHEAD OF THE LINE OF THUNDERSTORMS WAS UNSTABLE WITH SBCAPES
RUNNING UP TO 2500 J PER KG AND 00Z UPPER AIR ANALYSIS SHOWED
PRECIPITABLE WATER VALUES RUNNING IN EXCESS OF 1.5 INCH ALREADY IN
PLACE.  A CHANNEL OF WINDS IN THE LOW LEVELS WILL CONTINUE TO FEED
DEEP MOISTURE FROM THE GULF INTO THE AREA OVERNIGHT.  GIVEN BROAD
DIFLUENCE ALOFT BETWEEN THE SUBTROPICAL JET ALONG THE GULF COAST
REGION AND A POLAR JET TO THE NORTH...CONDITIONS SHOULD REMAIN
CAPABLE OF SUPPORTING HEAVY RAINFALL AHEAD OF THE CONVECTIVE LINE. 

A RUN OF THE HRRR TIME LAGGED ENSEMBLE FOCUSED THE AREA ALONG THE
TX/LA BORDER FOR A 30 PERCENT PROBABILITY OF 3 INCHES IN 3 HOURS
THROUGH 09Z.  OTHER HI RES CONVECTIVE ALLOWING MODELS WERE
POINTING TO THE POSSIBILITY OF RAFL RATES BEING ON THE ORDER 1.5
TO 2.5 INCH PER HOUR IN THE SAME AREA.  

FLASH FLOOD GUIDANCE ACROSS PARTS OF AR REMAIN QUITE LOW AFTER
HEAVY RAINFALL ON SATURDAY MORNING.  ADDITIONAL PROBLEMS WITH
FLOODING REMAINS A THREAT UNTIL THE HIGHER INTENSITY RAINFALL
MOVES OUT OF THE AREA OVERNIGHT. 

BANN

ATTN...WFO...EWX...FWD...HGX...JAN...LCH...LZK...SHV...

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

LAT...LON   35119293 35009132 32939176 30769373 29869544 
            30479733 32089548 33929383