AWUS01 KWNH 150528
FFGMPD
OHZ000-MIZ000-INZ000-WIZ000-ILZ000-151020-

Mesoscale Precipitation Discussion 0107
NWS Weather Prediction Center College Park MD
127 AM EDT Wed Apr 15 2026

Areas affected...northeastern IL/southeastern WI to southern
MI/northern IN

Concerning...Heavy rainfall...Flash flooding possible

Valid 150526Z - 151020Z

SUMMARY...Scattered flash flooding will be possible in the
vicinity of the eastern IL/WI border, eastward to southern Lower
MI, northern IN and northwestern OH. Rainfall rates of 1-2 in/hr
(locally higher) are expected along with peak additional rainfall
totals of 2-3 inches through 10Z

DISCUSSION...05Z radar imagery depicted a trailing stratiform MCS
moving across Lower MI with the leading edge pressing
southeastward across southern MI into northern IN. An outflow
boundary was analyzed ahead of the convective line from
southeastern MI into northern IN/IL with upstream thunderstorm
development occurring north of the western portion of the boundary
along the WI/IL border. 925-850 mb winds were from the SW at 45-55
kt to the south of the boundary over north-central IL and
1000-2000 J/kg MLCAPE extended from the MI/IN border back west to
the MS River, per SPC mesoanalysis data.

The leading edge of the MCS is expected to continue tracking
toward the ESE across southeastern MI into northern IN and
northwestern OH over the next 1 to 2 hours, but back to the west,
continued convective development is likely as moist, low level
flow overruns the slow moving western portion of the rain-cooled
outflow. Mean cell motions are generally from the west which will
setup a favorable pattern for training from west to east given
alignment with the low level boundary. Rainfall rates of 1 to 2
in/hr are likely (locally higher possible), and an additional 2 to
3 inches of rain is expected through 10Z where cell training is
maximized. Flash flood guidance is less than 2 inches in 3 hours
for some locations, especially across northern IL/southern WI
where heavy rain over the past 12-24 hours has contributed to
reduced soil infiltration.

Otto

...Please see www.wpc.ncep.noaa.gov for graphic product...

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

ATTN...RFC...MSR...TIR...NWC...

LAT...LON   43668276 43568226 43138209 42448225 41578312
            41298455 41268640 41468819 41788922 42428939
            42908878 42848652 42988484 43578350