Mesoscale Precipitation Discussion 0727
NWS Weather Prediction Center College Park MD
256 AM EDT Tue Aug 28 2018

Areas affected...Central Michigan

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

Valid 280655Z - 281255Z

Summary...An east-west oriented swath of heavy thunderstorms will
push east across central Michigan into the middle morning.

Discussion...A swath of heavy thunderstorms on the south side of
an MCC will continue to push east from WI and Lake MI across
central MI over the next several hours. This will at least be a
threat north of Muskegon where 3 to 6" of rain fell Monday
morning.

MLCAPE of 1000-1500 J/kg and PW of 1.8" to 2" is pushing in on a
50kt 850mb jet in the warm conveyor belt of a shortwave that
stretches all the way back over Minnesota per GOES-16 upper water
vapor imagery. While the north-south line over northern MI is
falling apart, this east-west boundary is expected spread east
across MI through the middle morning hours. Initial rain rates
reaching the western shore of Lake MI are only 0.5 to 1" per hour,
but this will be invigorated from the persistent low level jet for
several more hours.

Limited the eastward extent to the Saginaw Valley for now given
typical diurnal weakening of the low level jet expected by the
time the main part of the swath reaches that far east.

Jackson

ATTN...WFO...DTX...GRR...

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

LAT...LON   43928622 43788428 43798397 43488361 42778404
            42728427 43048648 43858671