SPC MD 467

MD 0467 CONCERNING SEVERE THUNDERSTORM WATCH 142… FOR SOUTHERN WISCONSIN…LAKE MICHIGAN

Mesoscale Discussion 0467
NWS Storm Prediction Center Norman OK
0722 AM CDT Fri Apr 18 2025

Areas affected...Southern Wisconsin...Lake Michigan

Concerning...Severe Thunderstorm Watch 142...

Valid 181222Z - 181415Z

The severe weather threat for Severe Thunderstorm Watch 142
continues.

SUMMARY...A severe threat will likely continue over the next couple
of hours from parts of southern Wisconsin eastward over Lake
Michigan. Significant wind gusts and large hail will be possible
with the strongest of cells.

DISCUSSION...The latest high-resolution radar imagery from KMKX
shows a cluster of strong to severe storms over southern Wisconsin,
with a severe short line segment located about 40 statute miles to
the west of Milwaukee, Wisconsin. The storms are located along an
east-to-west gradient of instability, where the RAP is estimating
MUCAPE around 1000 J/kg. RAP forecast soundings to the west of
Milwaukee still have a temperature inversion from the surface to 850
mb, with strong effective shear above the inversion. This will
continue to support elevated supercell development. In addition,
forecast soundings have steep lapse rates in the 700 to 500 mb
layer, which will aid a threat for large hail with supercells.
Hailstones greater than 2 inches in diameter will be possible in the
more intense cores. The stronger and faster moving line segments
could also produce severe gusts, with 70+ mph gusts possible. The
severe threat is expected to become more isolated later this
morning. To the east of the current watch, watch issuance probably
won't be needed. Trends will be monitored.

..Broyles/Gleason.. 04/18/2025

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

ATTN...WFO...GRR...LOT...MKX...ARX...

LAT...LON   43328623 42978610 42648625 42508658 42488814 42558932
            42619011 42769037 43059037 43369020 43578977 43598821
            43528671 43328623 

MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN

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