MESOSCALE PRECIPITATION DISCUSSION 0332
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1007 PM EDT TUE JUN 19 2018

AREAS AFFECTED...SOUTH-CENTRAL TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 200205Z - 200805Z

SUMMARY...MORE HEAVY RAIN EXPECTED OVERNIGHT WITH ADDITIONAL FLASH
FLOODING LIKELY.

DISCUSSION...THE LATEST GOES-16 CLEAN IR IMAGERY IS SHOWING SOME
COOLING CLOUD TOPS NEAR AND JUST EAST OF THE MID LEVEL LOW CENTER
OVER SOUTH-CENTRAL TX WHICH IS DRIFTING OFF TO THE WEST. RADAR
IMAGERY IS CONFIRMING SOME UPTICK IN CONVECTIVE BANDING WITH SOME
VERY HEAVY RAINFALL NOTED AROUND THE CORPUS CHRISTIE AREA.

EXPECT SOME ADDITIONAL CONVECTIVE ORGANIZATION OVER THE NEXT
SEVERAL HOURS NEAR AND EAST OF THE MID LEVEL LOW AS THE VORTICITY
CENTER TIGHTENS UP FURTHER AND COUPLES WITH VERY MOIST AND
CONVERGENT LOW LEVEL FLOW COMING IN OFF THE WESTERN GULF OF
MEXICO. THE AIRMASS JUST OFF THE COAST IS QUITE UNSTABLE TOO WITH
MLCAPE VALUES OF UP TO 1500 J/KG.

THE PWATS ACROSS THE REGION ARE VERY HIGH AND INDICATIVE OF A DEEP
TROPICAL COLUMN WITH VALUES AS HIGH AS 2.5 INCHES WHICH IS
CLASSICALLY REPRESENTED BY THE 00Z RAOB FROM KCRP. THIS WILL FAVOR
EXTREMELY HEAVY RAINFALL RATES THAT MAY REACH 3 TO 4 INCHES/HR
GIVEN THE COOLING CLOUD TOPS OVER THE REGION.

THE LATEST HIRES GUIDANCE LED BY THE HRRR AND HRRRX GUIDANCE
FAVORS AS MUCH AS 4 TO 6 INCHES OF RAIN AROUND THE IMMEDIATE
EASTERN FLANK OF THE MID LEVEL LOW CENTER. THESE ADDITIONAL RAINS
WILL CAUSE FLASH FLOODING AND SOME OF IT COULD BE SIGNIFICANT
GIVEN THE EARLIER HEAVY RAINS.

ORRISON

ATTN...WFO...BRO...CRP...EWX...HGX...

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

LAT...LON   29839789 29699696 29089642 28609638 28269647
            27839690 26999727 26679766 26729847 27229926
            27979950 28509939 29509860