MESOSCALE PRECIPITATION DISCUSSION 0275
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
144 PM EDT TUE MAY 31 2016
 
AREAS AFFECTED...NORTHERN IL...SOUTHERN WI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 311730Z - 312145Z
 
SUMMARY...SOME SLOW-MOVING AND REPEATING CONVECTION MAY RESULT IN
SOME FLASH FLOODING THIS AFTERNOON.

DISCUSSION...A BROKEN CLUSTER OF ELEVATED SHOWERS AND
THUNDERSTORMS IS ONGOING OVER NORTHERN IL AND ADVANCING NORTH INTO
SOUTHERN WI EARLY THIS AFTERNOON AS A BROAD WARM ADVECTION PATTERN
SPREADS OVER THE UPPER MIDWEST. CLOUD TOPS HAVE OVERALL TENDED TO
WARM WITH THE INITIAL ACTIVITY THAT DEVELOPED...BUT THERE HAS BEEN
SOME COOLING OF TOPS OVER NORTH-CENTRAL IL RECENTLY ALONG WITH AN
UPTICK IN LIGHTNING STRIKE ACTIVITY AS CONVECTION DEVELOPS FURTHER
WITHIN A SHARPENING INSTABILITY GRADIENT INVOLVING PROXIMITY OF A
STATIONARY FRONT.

OVER THE NEXT SEVERAL HOURS...HIRES MODEL OUTPUT STRONGLY
INDICATES ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE DEVELOPING
AND LIFTING NORTH WITHIN THE BROADER SCALE WARM ADVECTION PATTERN.
RAINFALL RATES OF 1.5 TO 2.0 INCHES/HR ARE EXPECTED AND GIVEN SOME
RISK OF CELLS FALLING OVER AREAS EARLIER HIT BY HEAVY
RAINFALL...SOME FLASH FLOODING IS POSSIBLE.

ORRISON

ATTN...WFO...ARX...DVN...GRB...ILX...LOT...MKX...

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

LAT...LON   44238927 43648851 42168834 41228837 40838876 
            41098972 41509013 42639038 43459037 44129003