MESOSCALE PRECIPITATION DISCUSSION 0287
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1139 PM EDT WED JUL 01 2015
 
AREAS AFFECTED...SOUTHEAST IL...SOUTHWEST IN...CENTRAL AND WESTERN
KY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 020339Z - 020700Z
 
SUMMARY...VERY HEAVY SHOWERS AND THUNDERSTORMS TO CONTINUE OVER
THE NEXT COUPLE OF HOURS...WITH A WEAKENING TREND EXPECTED AFTER
06Z. ADDITIONAL FLASH FLOODING IS EXPECTED IN THE SHORT-TERM.

DISCUSSION...IR SATELLITE IMAGERY SHOWS CONVECTIVE CLOUD TOPS
CONTINUING TO COOL ACROSS PORTIONS OF SOUTHEAST IL AND SOUTHWEST
IN AS A SHORTWAVE IMPULSE DIGGING SOUTHEAST ACROSS THE MIDWEST
INTERACTS WITH A FRONTAL ZONE DRAPED ACROSS THE OH RIVER VALLEY.
GOES-SOUNDER PWATS ARE VERY HIGH IN VICINITY OF THE FRONT...WITH
VALUES LOCALLY EXCEEDING 2 INCHES. THIS MOISTURE POOLED ALONG THE
BOUNDARY IS FACILITATING VERY INTENSE RAINFALL RATES...AND WHILE
THERE IS A VERY MODEST DEGREE OF INSTABILITY IN PLACE...THE
APPROACH OF THE SHORTWAVE ENERGY HAS BEEN ABLE TO COMPENSATE AND
ALLOW FOR RELATIVELY DEEP CONVECTION TO PERSIST THROUGH THE LATE
EVENING HOURS.

HIRES MODEL GUIDANCE HAS NOT BEEN HANDLING THE DEGREE OF
CONVECTIVE ORGANIZATION PARTICULARLY WELL...BUT IT IS ANTICIPATED
THAT THE STRONGER THERMODYNAMICS WILL REMAIN FOCUSED FARTHER WEST
OVERNIGHT WITH THE CONVECTION IMPACTING MUCH OF CENTRAL MO AT THIS
TIME. LOW LEVEL INFLOW INTO THE CURRENT CONVECTION OVER IL/IN IS
RATHER WEAK AND IS EXPECTED TO REMAIN THAT WAY WITH GENERALLY
ABOUT 20 KTS OF 850 MB FLOW. DESPITE THE SHORT-TERM SUSTAINABILITY
OF THE CONVECTION...ADDITIONAL DECLINE IN INSTABILITY AND A LACK
OF LOW LEVEL JET ENERGY SHOULD FOSTER A WEAKENING TREND BY AROUND
06Z WITH THE CONVECTION AND ESPECIALLY THEREAFTER. UNTIL
THEN...INTENSE RAINFALL RATES WILL CONTINUE LOCALLY AND ADDITIONAL
FLASH FLOODING WILL BE EXPECTED SINCE THE CONVECTION HAS BEEN
TENDING TO LOCALLY TRAIN AND BACKBUILD OVER THE SAME AREA. WILL
CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...ILX...IND...LMK...PAH...

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

LAT...LON   39028741 38498626 37688507 37188524 37148607 
            37408712 37978830 38468868 38968866 
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