MESOSCALE PRECIPITATION DISCUSSION 0307
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
726 AM EDT SAT JUN 04 2016
 
AREAS AFFECTED...UPPER TX COAST...SOUTHWEST LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 041120Z - 041430Z
 
SUMMARY...VERY INTENSE RAINFALL RATES ALONG THE UPPER TX COAST
WILL ADVANCE INTO SOUTHWEST LA OVER THE NEXT COUPLE OF HOURS.
FLASH FLOODING IS POSSIBLE CONSIDERING THE NEARLY SATURATED
GROUNDS OVER THE REGION.

DISCUSSION...AN EXPANSIVE AREA OF COLD-TOPPED CONVECTION CONTINUES
TO FOCUS GENERALLY ALONG AND JUST OFF THE SOUTHEAST TX COAST IN
ASSOCIATION WITH A SURFACE TROUGH AND WITHIN A RATHER STRONGLY
DIVERGENT FLOW PATTERN ALOFT.

HOWEVER THE NORTHEAST FLANK OF THE CONVECTION HAS BEEN PIVOTING A
BIT AROUND THE EAST SIDE OF THE UPPER LOW OVER EAST-CENTRAL
TX...AND THIS HAS ALLOWED CONVECTION TO LIFT FARTHER NORTHEAST
ALONG THE UPPER TX COAST...AND OVER THE NEXT FEW HOURS IT WOULD
APPEAR THAT THE ACTIVITY WILL SUSTAIN ITSELF INTO SOUTHWEST LA.
THIS WILL BE AIDED BY A RATHER STRONG INSTABILITY GRADIENT
SITUATED ACROSS THE NORTHWEST GULF OF MEXICO JUST AHEAD OF THIS
CONVECTIVE BAND...AND ALSO THE PERSISTENT LEVEL OF FORCING ALOFT
AND LOW LEVEL MOISTURE/INSTABILITY TRANSPORT.

THE BLENDED-TPW PRODUCT SHOWS PWATS OF 1.8 TO 2.0 INCHES OVER THE
REGION...AND ACTUALLY THE CIRA LPW PRODUCT INDICATES A FAIR DEGREE
OF MOISTURE POOLED HIGH UP IN THE 300/500 MB LAYER WHICH WITH A
LACK OF ANY MID LEVEL DRY AIR SUGGESTS A HIGHLY EFFICIENT
ENVIRONMENT FOR HEAVY RAINFALL.

EXPECT THE POTENTIAL FOR 2 TO 4 INCHES OF ADDITIONAL RAIN THROUGH
MID-MORNING...AND AGAIN THE WET ANTECEDENT CONDITIONS WILL PROMOTE
ADDITIONAL RUNOFF AND FLASH FLOOD CONCERNS.

ORRISON

ATTN...WFO...HGX...LCH...

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

LAT...LON   30439310 30239251 29699248 29539286 29629340 
            29599380 29319472 29889468 30379390