MESOSCALE PRECIPITATION DISCUSSION 0181
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
557 PM EDT SUN JUN 07 2015
 
AREAS AFFECTED......SOUTHEAST IA/NORTHEAST MOL.NORTH CENTRAL
IL/NORTHWEST IN... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 072200Z - 080200Z
 
SUMMARY...TRAINING OF CONVECTIVE CELLS AHEAD OF A COLD FRONT
ACROSS PORTIONS OF NORTH CENTRAL IL AND NORTHWEST IN COULD RESULT
IN FLASH FLOODING.

DISCUSSION...CONVECTION HAS DEVELOPED ACROSS NORTH CENTRAL IL
WHERE THE REMAINING INHIBITION HAS BEEN REMOVED. SPC MESOANALYSIS
SHOWED AN AXIS OF 2500-3500 J/KG OF MLCAPE STRETCHING FROM
SOUTHEAST IA THROUGH NORTH CENTRAL IL...AND THE CONVECTION HAS
TAPPED INTO THE 1.90 INCH PRECIPITABLE WATER AIR OVER THAT AXIS.
CELLS SOUTH OF KORD HAVE PRODUCED RAINFALL RATES IN EXCESS OF 1.50
INCHES/HOUR. KLOT RADAR SHOWED HOURLY RAINFALL RATES IN EXCESS OF
2.50 INCHES AN HOUR...BUT GIVEN THE HIGH CAPE ENVIRONMENT...THIS
IS LIKELY HAIL CONTAMINATED.

MEANWHILE....THE CONVECTION THAT FORMED OVER SOUTHEAST IA HAS NOT
BEEN WELL MODELED BY THE HIGH RESOLUTION SOLUTIONS. GIVEN THE
UNIDIRECTIONAL LOW TO MID LEVEL FLOW AHEAD OF THE COLD FRONT
DROPPING SOUTHEAST...THIS CONVECTION IS EXPECTED TO TRACK OVER
NORTH CENTRAL IL...RESULTING IN THE POTENTIAL FOR TRAINING AND THE
POTENTIAL FOR FLASH FLOODING. 

WHILE THE CONVECTION SHOULD BE OUTFLOW DOMINATED (AT LEAST
INITIALLY)...THERE IS A FAIRLY GOOD HIGH RESOLUTION MODEL
CONSENSUS FOR HEAVY RAINFALL POTENTIAL ACROSS NORTH CENTRAL IL
INTO NORTHWEST IN. HOWEVER... THERE IS SOME SPREAD IN THE EXPECTED
RAINFALL AMOUNTS...WHICH THE LATEST EXPERIMENTAL HRRR AND 12Z NSSL
WRF SUGGEST THE POTENTIAL FOR LOCAL 2-4 INCH RAINFALL
AMOUNTS...ESPECIALLY WHERE TRAINING OCCURS. ONE AND THREE HOUR
FLASH FLOOD GUIDANCE VALUES ARE AS LOW AS 1.50 TO 2.00 INCHES
ACROSS PORTIONS OF WEST CENTRAL IL...FLASH FLOODING IS CONSIDERED
POSSIBLE.

HAYES

ATTN...WFO...DVN...ILX...IND...IWX...LOT...LSX...

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

LAT...LON   41748784 41188617 40248664 39818914 39899153 
            40609216 40859205 40849208 41639055