867
ACUS11 KWNS 220445
SWOMCD
SPC MCD 220445
MIZ000-WIZ000-220645-

Mesoscale Discussion 0885
NWS Storm Prediction Center Norman OK
1145 PM CDT Tue May 21 2024

Areas affected...Parts of eastern Wisconsin...northwestern lower
Michigan and eastern Upper Michigan

Concerning...Severe potential...Watch unlikely

Valid 220445Z - 220645Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorm activity appears likely to continue
weakening, but could still pose some risk for strong to severe gusts
through 3-4 AM EDT.

DISCUSSION...Although seasonably moist inflow with sizable CAPE is
probably being maintained into lingering thunderstorm activity
spreading into and through the upper Great Lakes region, convection
is likely becoming elevated above cool, stable air over Lake
Michigan.  At the same time, with continuing slow diurnal cooling, a
modestly moist boundary-layer over inland portions of lower Michigan
and eastern upper Michigan remains only weakly unstable at best.

While evaporative cooling in the sub-cloud layer may contribute to
the downward transport of 50+ kt flow to the surface, severe weather
potential appears likely to otherwise continue to diminish through
the next few hours.  As the supporting mid-level short wave trough
pivots northward toward the Lake Superior vicinity, it appears the
weakening leading line of convection could graze northwestern lower
Michigan coastal areas and overspread eastern upper Michigan, while
the weakening trailing line overspreads its outflow, near/east of
the Green Bay vicinity toward the eastern upper peninsula of
Michigan through 07-08Zz.

..Kerr.. 05/22/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...APX...GRR...MQT...GRB...MKX...

LAT...LON   46998523 45938435 44018648 43798722 42788800 43548841
            44618798 45968678 47068662 46998523