MESOSCALE PRECIPITATION DISCUSSION 0322
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
713 AM EDT WED JUN 14 2017

AREAS AFFECTED...SOUTHERN LAKE MI TO UPPER OH VALLEY

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

VALID 141112Z - 141712Z

SUMMARY...THUNDERSTORMS ARE BEGINNING TO INCREASE IN COVERAGE OVER
AN AREA OF PARTIALLY SATURATED SOILS FROM YESTERDAY.  HOURLY RAIN
RATES UP TO 2.5" WITH LOCAL AMOUNTS UP TO 4" ARE POSSIBLE OVER THE
NEXT SEVERAL HOURS.

DISCUSSION...AN UPPER LOW NEAR THE SOUTHERN END OF LAKE MICHIGAN
COMBINED WITH AN MCV ACROSS NORTH-CENTRAL IN AND WEAK BAROCLINIC
BOUNDARIES ACROSS THE REGION APPEAR TO BE HELPING WITH A NEW
CONVECTIVE UPTICK ACROSS PORTIONS OF IN, OH, AND NORTHERN KY. 
RECENT RAP GUIDANCE INDICATES A DEVELOPING 850 HPA CONVERGENCE
ZONE NEAR THE BURGEONING THUNDERSTORMS. PRECIPITABLE WATER VALUES
OF 1.5-1.75" LIE ACROSS THE REGION PER GPS INFORMATION.  MUCAPES
ARE 500-1000 J/KG, JUST SUFFICIENT FOR THE RENEWED CONVECTION. 
INFLOW AT 850 HPA IS SIMILAR TO YESTERDAY, 15-20 KTS AND SLIGHTLY
CONVERGENT ACROSS IN, SOUTHWEST OH, AND NORTHEAST KY WHICH
SLIGHTLY EXCEEDS THE MEAN 850-400 HPA WIND.  UNLIKE YESTERDAY,
EFFECTIVE BULK SHEAR OF 25-30 KTS EXISTS NEAR THE UPPER LOW ACROSS
NORTHEAST IL AND NORTHWEST IN.

OUTSIDE OF THE 06Z CANADIAN REGIONAL MODEL, THE GUIDANCE APPEARS
TO BE DELAYED IN THE FORMATION OF CONVECTION IN THIS REGION. 
DAYTIME HEATING SHOULD LEAD TO AN ADDITIONAL 1000-1500 J/KG
MLCAPES WITHIN THE INSTABILITY POOL ACROSS IL AND WESTERN KY, WITH
CONVECTION EXPECTING TO FORM DOWNWIND AND PERHAPS REACHING WV WITH
TIME. OF CONCERN IS A WEAKER BOUNDARY LAYER MOISTURE CONVERGENCE
SIGNAL IN THE RAP GUIDANCE.  A COMBINATION PULSE AND LOOSELY
ORGANIZED CONVECTION COULD LEAD TO BRIEF PERIODS OF TRAINING AND
CELL MERGERS.  HOURLY RAIN RATES UP TO 2.5" WITH LOCAL AMOUNTS UP
TO 4" COULD LEAD TO ISSUES WHERE SOILS ARE PARTIALLY SATURATED
FROM YESTERDAY'S RAINFALL.

ROTH

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

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

LAT...LON   41678490 41198270 40398156 39928129 39048127
            38058260 38178439 39338603 40388691 41158723
            41608676