MESOSCALE PRECIPITATION DISCUSSION 0223
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1231 AM EDT TUE JUN 16 2015
 
AREAS AFFECTED...ERN ILLINOIS INTO WRN PENNSYLVANIA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 160430Z - 160830Z
 
SUMMARY...LINGERING INSTABILITY...DEEP MOISTURE AND A FAVORABLE
SETUP FOR TRAINING CONVECTION WILL EXTEND THE FLASH FLOOD THREAT
FOR ANOTHER FEW HOURS. HOWEVER...A GRADUAL DIMINISHING OF FLASH
FLOOD CONCERNS IS EXPECTED AS THE NIGHT PROGRESSES AS INSTABILITY
LESSENS.

DISCUSSION...REGIONAL RADAR IMAGERY AS OF 04Z CONTINUED TO SHOW
WIDESPREAD SHOWERS AND THUNDERSTORMS EXTENDING FROM CNTRL ILLINOIS
TO WRN PENNSYLVANIA. MODIFIED FOR CURRENT
TEMPERATURE/DEWPOINTS...00Z AREA RAOBS SUGGEST ELEVATED
INSTABILITY OF 500 TO 1000 J/KG REMAINS ACROSS PORTIONS OF THE
MIDWEST WITH A FEW BURSTS OF COOLING SEEN ON INFRARED SATELLITE
IMAGERY OVER CNTRL/NRN INDIANA...AND CNTRL OHIO. THE ENTIRE REGION
REMAINS VERY MOIST WITH PRECIPITABLE WATER VALUES CENTERED AROUND
2 INCHES PER RECENT GPS OBSERVATIONS AND FLOW IS UNIDIRECTIONAL
FROM THE WEST SUPPORTING REPEATING CELL MOTIONS.

SHOWERS AND THUNDERSTORMS WILL PERSIST INTO THE NIGHT AHEAD OF A
POSITIVELY TILTED UPPER TROUGH...CURRENTLY MOVING INTO THE UPPER
GREAT LAKES REGION. SOME WEAK SUPPORT FOR LIFT MAY BE SUPPORTED BY
SUBTLE RIGHT ENTRANCE REGION LIFT WITHIN THE SRN PORTION OF AN
UPPER JET MAX ON THE LEE SIDE OF THE UPPER TROUGH. GIVEN THE
ABUNDANT MOISTURE IN PLACE AND A FAVORABLE SETUP FOR REPEATING
CONVECTION...FEEL A FEW MORE POCKETS OF FLASH FLOODING WILL REMAIN
POSSIBLE ANYWHERE BETWEEN E-CNTRL ILLINOIS TO WRN PENNSYLVANIA
BEFORE INSTABILITY FURTHER WANES INTO THE NIGHT. 

RECENT RUNS OF THE HRRR AND EXPERIMENTAL HRRR SUPPORT THIS IDEA
WITH 1-2 IN/HR RATES WITHIN SOME OF THE STRONGER RAIN CORES. THIS
WILL BE ESPECIALLY PROBLEMATIC ACROSS NRN AND ERN PORTIONS OF THE
THREAT AREA WHERE 1 HR FFG IS ONLY 1 IN/HR.

OTTO

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

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

LAT...LON   41048390 40898218 40808069 40587979 40207961 
            39448025 39378220 39258687 39338808 39598865 
            40278866 40778737 40958590