MESOSCALE PRECIPITATION DISCUSSION 0017
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
104 AM EDT FRI APR 19 2013
 
AREAS AFFECTED...CNTRL AND NERN IND...NWRN OH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 190504Z - 190904Z
 
SUMMARY...A SFC COLD FRONT CONTINUES TO ADVANCE SLOWLY FROM WEST
TO EAST...WITH A LARGE AREA OF MDT TO LOCALLY HVY RAINFALL
ATTENDANT TO IT. LOW FFG VALUES SUGGEST LOCALIZED RUNOFF
PROBS/FLASH FLOODING WILL BE POSSIBLE.

DISCUSSION...RADAR AND SAT IMAGERY SHOW A PERSISTENT AXIS OF
CONVECTION MOVING GRADUALLY THROUGH THE OH VALLEY...WITH LITTLE
OVERALL CHANGE IN INTENSITY NOTED OVER THE LAST COUPLE OF HRS. THE
SSW/NNE ORIENTED CONVECTIVE LINE IS ASSOCIATED WITH A SLOW-MOVING
COLD FRONT AND A LARGER SCALE UPPER TROUGH THAT IS ADVANCING INTO
THE OH VALLEY FROM THE PLAINS/MS VALLEY. THIS WILL CONTINUE TO
PROVIDE LARGE SCALE ASCENT OVER THE THREAT AREA THE NEXT FEW
HRS...WITH FORCING LOCALLY ENHANCED AS A RESULT OF AN OUTFLOW
BOUNDARY EXTENDING EAST OF THE COLD FRONT FROM JUST NORTH OF A
LINE FROM SHELBYVILLE TO DAYTON TO CANTON-AKRON. A MOIST AND
ROBUST LOW LEVEL JET IS ALREADY IN PLACE...ON THE ORDER OF 50 KTS
LOCALLY AND IS OVERRUNNING THE OUTFLOW BOUNDARY. THEREFORE THE
ONGOING CONVECTIVE ACTIVITY IS LIKELY TO TEND TO SUSTAIN ITSELF AT
LEAST FOR THE NEXT 2 TO 3 HRS...BEFORE THEN WEAKENING AS SUPPORTED
BY THE 00Z NAM-CONEST. GIVEN THE PERSISTENT RAINFALL FALLING OVER
LOCALLY SATURATED GROUND...FLASH FLOODING CANNOT BE RULED OUT.
WILL CONTINUE TO MONITOR.

ORRISON


ATTN...WFO...ILN...IWX...IND...

LAT...LON   40488433 40028488 39608562 39498634 39908666 40778625
            41238577 41638483 41508416 40988393 40488433