Graphic for MPD #0463

MESOSCALE PRECIPITATION DISCUSSION 0463
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
141 AM EDT TUE JUL 11 2017

AREAS AFFECTED...CENTRAL/EASTERN IN...OH

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 110540Z - 111000Z

SUMMARY...THE THREAT FOR SOME ADDITIONAL FLASH FLOODING CONTINUES
AS SMALL CLUSTERS OF HEAVY SHOWERS AND THUNDERSTORMS CONTINUE TO
DEVELOP OVER THE REGION ALONG A FRONTAL ZONE.

DISCUSSION...CLUSTERS OF HEAVY SHOWERS AND THUNDERSTORMS CONTINUE
TO DEVELOP ACROSS PORTIONS OF CENTRAL/EASTERN IN AND ACROSS OH
ALONG A WAVY QUASI-STATIONARY FRONT AND OUT AHEAD OF A WAVE OF LOW
PRESSURE. FAVORABLE INSTABILITY IS IN PLACE WITH AS MUCH AS 1000
TO 2000 J/KG OF MUCAPE POOLED ALONG THE FRONT...ESPECIALLY OVER
CENTRAL/NORTHERN IN...BUT THE CONVECTION IS ALSO IN AN ENVIRONMENT
OF MODEST DEEP LAYER ASCENT ASSOCIATED WITH A MID/UPPER LEVEL
SHORTWAVE TROUGH CROSSING THE OH VALLEY AND ALSO WITH THE NOSE OF
A WEAK UPPER LEVEL JET STREAK OF ABOUT 50 TO 70 KTS NOW MOVING
ACROSS NORTHERN IL. THERE IS ALSO A LOW LEVEL JET OF ABOUT 40 TO
45 KTS OUT OF THE SOUTHWEST AS PER LATEST VWP DATA CROSSING THE OH
RIVER VALLEY AHEAD OF THE WAVE OF LOW PRESSURE AND THIS IS
FOCUSING A WELL-DEFINED WARM ADVECTION PATTERN WITH PLENTY OF
MOISTURE/INSTABILITY TRANSPORT ALONG AND OVER THE FRONTAL ZONE.

CONDITIONS WILL LIKELY REMAIN CONDUCIVE FOR ADDITIONAL CONVECTION
TO DEVELOP AND LOCALLY BACKBUILD ALONG THE FRONTAL ZONE FROM
CENTRAL IN EAST ACROSS OH...WITH PERHAPS A GRADUAL TENDENCY FOR
THE ACTIVITY TO SETTLE A LITTLE FARTHER SOUTH. GIVEN PWATS OF OVER
1.5 INCHES...AND THE VERY COLD CONVECTIVE TOPS...RAINFALL RATES OF
NEAR 2 INCHES/HR WILL BE POSSIBLE. THE LATEST HRRR/HRRRX GUIDANCE
SUGGEST AS MUCH AS ANOTHER 3 TO 4 INCHES LOCALLY THROUGH
DAWN...AND WITH ALREADY MULTIPLE ROUNDS OF HEAVY RAIN SEEN
EARLIER...THE ADDITIONAL RAIN WILL CONTINUE TO PROMOTE CONCERNS
FOR RUNOFF AND FLASH FLOODING. IT IS EXPECTED THOUGH THAT
CONDITIONS WILL IMPROVE TOWARD DAWN...BUT WILL CONTINUE TO MONITOR
THE CONVECTIVE TRENDS.

ORRISON

ATTN...WFO...CLE...ILN...IND...IWX...LOT...PBZ...RLX...

ATTN...RFC...NCRFC...OHRFC...

LAT...LON   41328537 41308406 41078297 40638183 39938116
            39348147 39058193 38868322 39108492 39448584
            39688649 40418703 40938705 41308659


Last Updated: 141 AM EDT TUE JUL 11 2017