MESOSCALE PRECIPITATION DISCUSSION 0567
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
715 AM EDT SUN AUG 14 2016
 
AREAS AFFECTED...SOUTHERN IL...CENTRAL/SOUTHERN IN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 141110Z - 141600Z
 
SUMMARY...SLOW-MOVING HEAVY RAINS THIS MORNING MAY CAUSE SOME
RUNOFF PROBLEMS AND POSSIBLE FLASH FLOODING GIVEN WET ANTECEDENT
CONDITIONS

DISCUSSION...GOES-14 SRSOR IR 1-MINUTE IMAGERY SHOWS THE
PERSISTENCE OF CONVECTION ALONG AN AXIS FROM SOUTHERN IL INTO
PORTIONS OF CENTRAL AND SOUTHERN IN. THERE HAS BEEN A TENDENCY FOR
THE CONVECTION TO TRAIN OVER THE SAME AREA OVER THE LAST COUPLE OF
HOURS...AND SOME OF THESE RAINS WILL BE FALLING OVER AREAS THAT
SAW HEAVY RAIN YESTERDAY.

THE CONVECTION IS FORMING IN CLOSE PROXIMITY TO A QUASI-STATIONARY
FRONT NORTH OF THE OH RIVER...AND THIS FRONT HAS BEEN THE FOCUS
FOR THE POOLING OF DEEP TROPICAL MOISTURE THAT IS IN PART RELATED
TO THE BROAD LOW LEVEL CIRCULATION THAT IS IMPACTING THE LOWER MS
VALLEY.

THERE IS EXPECTED TO BE SOME POTENTIAL FOR THE CONVECTION TO
BECOME A BIT MORE CONCENTRATED AND STRONGER OVER THE NEXT COUPLE
OF HOURS AS 250 MB RIGHT-ENTRANCE REGION JET DYNAMICS TRAVERSE THE
AREA AND PROVIDE SOME DYNAMICAL FORCING. HOWEVER...THE HRRR AND
HRRRP GUIDANCE SUGGEST THIS FORCING WEAKENING TOWARD MIDDAY...AND
SO IT WOULD APPEAR AS IF THE ACTIVITY SHOULD BE A CONCERN FOR A
FEW HOURS BEFORE THEN CYCLING DOWN.

THE PWATS REMAIN OVER 2 INCHES OVER THE OH RIVER VALLEY WHICH WILL
CONTINUE TO SUPPORT HEAVY RAINFALL RATES...AND THE AFOREMENTIONED
HIRES GUIDANCE DOES SUGGEST AS MUCH AS AN ADDITIONAL 2 TO 4 INCHES
OF RAIN THROUGH MIDDAY BEFORE THE CONVECTION WANES. THIS WILL FALL
OVER SATURATING SOILS...AND THUS CONCERNS WILL EXIST FOR SOME
RUNOFF AND/OR FLASH FLOODING.

ORRISON

ATTN...WFO...ILN...ILX...IND...LSX...PAH...

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

LAT...LON   40218478 39808462 39458493 38858640 38268794 
            37838943 38209013 38729008 38948966 39108898 
            39338831 39798716 40208586