AWUS01 KWNH 281936
FFGMPD
OHZ000-MIZ000-282235-

Mesoscale Precipitation Discussion 0819
NWS Weather Prediction Center College Park MD
335 PM EDT Mon Jul 28 2025

Areas affected...southeastern Michigan

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

Valid 281935Z - 282235Z

Summary...Areas of urban flash flooding are possible near the
Detroit Metropolitan area over the next couple hours.

Discussion...A fairly progressive linear complex was moving into
southeastern Michigan and extends from near Ann Arbor
southwestward to the MI/IN border near Coldwater. Ahead of this
complex, nearly stationary cells were developing in a very
moist/buoyant airmass (2+ inch PW values and 3000 J/kg MLCAPE)
supporting heavy rainfall. Several spots of 1 inch/hr rain rates
were developing (as estimated per MRMS). An addition, cells were
merging with the MCS and with other nearby convection in the
discussion area, resulting in prolonging of rainfall rates. The
net result of this pattern is scattered areas of increasing rain
rates, which could conceivably reach 2-3 inches/hr over the next
1-2 hours. These rates are expected to cause at least
spotty/isolated runoff/flood issues particularly near urban and
sensitive areas of southeastern Michigan.

This threat is expected to be relatively short lived, however. As
the aforementioned linear MCS reaches western Lake Erie, upstream
areas should experience a temporary stabilization of the low-level
airmass, reducing the thunderstorm threat over the region. Flash
flood potential should also wane for a few hours behind the line
(after around 22Z or so).

Cook

ATTN...WFO...CLE...DTX...GRR...IWX...

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

LAT...LON 42858371 42848266 41908203 41538263 41788458
41938476

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