Mesoscale Precipitation Discussion 0754
NWS Weather Prediction Center College Park MD
216 PM EDT Mon Sep 03 2018

Areas affected...Southern MI, Northwest OH, & Northern IN

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

Valid 031815Z - 032215Z

Summary...Thunderstorms are attempting to train from northern IN
into southeast MI.  Hourly totals to 2" with local amounts to 4"
are possible.

Discussion...Satellite and radar data indicate a training band of
convection is beginning to form near a thermal boundary across
northern IN and southeast MI.  Inflow at 850 hPa is convergent at
20-30 kts per VAD wind profiles.  Effective bulk shear in the
region is 20 kts, which combined with unidirectional flow out of
the west-southwest is attempting to form the band.  Precipitable
water values are ~1.75" per GPS data.  ML CAPE values are
1000-2000 J/kg.

While the mesoscale guidance is unimpressed here, the ingredients
are there for heavy rainfall.  Outflow boundaries may force some
eastward shift to this convection in a couple of hours, though it
shouldn't be significant.  Hourly totals to 2" with local amounts
to 4" are possible.  Considering the relative lack of signal in
the mesoscale guidance, used a four hour window and the possible
category.

Roth

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

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

LAT...LON   42678288 42428280 42318258 42088251 41788330
            41608296 41538299 41018487 40958554 41058741
            42148605 42608372