MESOSCALE PRECIPITATION DISCUSSION 0049
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
522 PM EDT MON MAY 12 2014
 
AREAS AFFECTED...SOUTHEAST WI...NORTHERN IL...SOUTHERN MI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 122121Z - 130321Z
 
SUMMARY...AN INCREASE OF LOW-LEVEL INFLOW INTO AND OVER A
CONVERGENCE ZONE IS EXPECTED ACROSS A SATURATED AREA OVER THE NEXT
SEVERAL HOURS.  REGIONAL FLASH FLOODING IS POSSIBLE.

DISCUSSION...A ZONE OF CONVERGENCE, WITH SOME ASSOCIATED
TEMPERATURE CONTRAST, HAS BEEN SET UP ACROSS SOUTHERN MI DURING
THE PAST SEVERAL HOURS DUE TO SCATTERED THUNDERSTORMS MOVING
THROUGH THE REGION.  FLASH FLOOD GUIDANCE VALUES HAVE FALLEN CLOSE
TO 1-1.5" IN THREE HOURS DUE TO RECENT RAINS. PRECIPITABLE WATER
VALUES ARE NEAR 1.50", NEAR THE 90TH PERCENTILE FOR MID-MAY.  CAPE
VALUES ARE NEAR 2000 J/KG. 

INFLOW AT 850 HPA IS EXPECTED TO INCREASE INTO THE CONVERGENCE
ZONE THROUGH 04Z, WHICH IS EXPECTED TO CAUSE INCREASED CONVECTIVE
ORGANIZATION -- TO A MORE FAVORABLE MULTI-CELL ENVIRONMENT -- AND
BACKBUILDING OF CELLS, MAINLY AFTER 23Z.  DUE TO LOSS OF DAYTIME
HEATING, SOME CIN MAY DEVELOP ALONG THE CONVERGENCE ZONE, CAUSING
CONVECTION TO BECOME MORE ELEVATED THIS EVENING.  LOCAL RAINFALL
AMOUNTS OF 2-3" ARE EXPECTED, WHICH COULD CAUSE REGIONAL FLASH
FLOODING.

ROTH

ATTN...WFO...DTX...IWX...GRR...LOT...MKX...

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

LAT...LON   41728324 42278403 42478513 42298607 42068671 42148764
            42588893 43138886 43338738 43448589 43568391 44068259
            42488260 41728324