MESOSCALE PRECIPITATION DISCUSSION 0384
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
235 PM EDT SUN JUL 01 2018

AREAS AFFECTED...NRN IL...ERN WI INTO THE CNTRL AND ERN U.P. OF MI

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 011834Z - 020030Z

SUMMARY...FLASH FLOODING WILL BE POSSIBLE ACROSS NORTHERN
ILLINOIS...EASTERN WISCONSIN INTO THE U.P. OF MICHIGAN THROUGH
00Z. THE POTENTIAL EXISTS FOR TRAINING CONVECTION WITH RAINFALL
RATES OF 1.5 TO 2.5 IN/HR AND 6 HOUR TOTALS OF 2-4 INCHES.

DISCUSSION...CONVECTION WAS ONGOING ACROSS NORTHEASTERN WISCONSIN
AS OF 18Z WITH CELLS REPEATING IN A SOUTHWEST TO NORTHEAST FASHION
WITH REPORTED RAINFALL RATES AS HIGH AS 1.8 IN/HR NEAR
TIGERTON...CLOSE TO BUT SLIGHTLY LOWER THAN KGRB RAINFALL
ESTIMATES THROUGH 1730Z. PRECIPITABLE WATER VALUES WERE OBSERVED
BETWEEN 1.5 AND 1.9 INCHES WITHIN A CORRIDOR OF DEEP MOISTURE
WHICH EXTENDED SOUTHWESTWARD INTO WEST TEXAS. CONVECTION WAS
FIRING OUT AHEAD OF AN ADVANCING 700-500 MB TROUGH AXIS OVER
EASTERN MINNESOTA WITHIN A REGION OF STRONGER 850-700 MB MEAN WIND
SPEEDS...OBSERVED BETWEEN 35-50 KT ON AREA VAD WIND
PLOTS...HELPING THE POTENTIAL OF REPEATING/TRAINING HEAVY RAIN
CORES. GENERALLY CLEAR SKIES ACROSS SOUTHERN WISCONSIN INTO
NORTHERN ILLINOIS DURING THE EARLY AFTERNOON HAVE ALLOWED MLCAPE
VALUES TO REACH 1000-2500+ J/KG VIA THE LATEST SPC MESOANALYSIS.

18Z SURFACE OBSERVATIONS PLACED A PRE-FRONTAL TROUGH AXIS WHICH
EXTENDED FROM SOUTHWESTERN WISCONSIN INTO FAR WESTERN
ILLINOIS...COINCIDENT WITH NEW STORM DEVELOPMENT OVER THE PAST
HOUR. STORMS ARE EXPECTED TO CONTINUE EXPANDING INTO THE
INSTABILITY AXIS OUT AHEAD OF THE PRE-FRONTAL TROUGH AND COLD
FRONT...WHICH ARE EXPECTED TO REACH SOUTHERN LAKE MICHIGAN BETWEEN
21-00Z. GIVEN THE NEGATIVELY TITLED TROUGH AXIS ALOFT...THE DEEPER
MOISTURE IS EXPECTED TO CLEAR WISCONSIN AND THE CENTRAL U.P. OF
MICHIGAN EARLIER THAN NORTHERN ILLINOIS WHERE STORMS ARE EXPECTED
TO LINGER A BIT LONGER. FLASH FLOOD GUIDANCE IS LOWERED DUE TO
RECENT RAINFALL ACROSS PORTIONS OF NORTHERN WISCONSIN INTO THE
MICHIGAN U.P. AS WELL AS ALONG THE WISCONSIN/ILLINOIS
BORDER...WITH THESE AREAS POTENTIALLY MORE SUSCEPTIBLE TO FLASH
FLOODING

OTTO

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

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

LAT...LON   46878616 46568578 45988602 44978689 43058723
            41548789 41018912 41128975 41439006 41849019
            43259027 44718985 45998883 46818771