ACUS11 KWNS 241745
SWOMCD
SPC MCD 241744=20
MIZ000-INZ000-WIZ000-ILZ000-IAZ000-MNZ000-242015-

Mesoscale Discussion 1292
NWS Storm Prediction Center Norman OK
1244 PM CDT Wed Jun 24 2026

Areas affected...portions of Wisconsin into northern Illinois and
northwest Indiana

Concerning...Severe potential...Watch possible=20

Valid 241744Z - 242015Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated large hail and damaging wind gusts will be
possible with thunderstorms this afternoon into early evening. A
severe thunderstorm watch may be needed in the next couple of hours.

DISCUSSION...Convection is already developing at midday near the MS
River into northwest WI where stronger heating has resulted in 1000
J/kg MLCAPE near an area of surface low pressure and moderate
westerly flow aloft. Thunderstorms are expected to gradually
increase in coverage and intensity through the afternoon with
east/southeast extent across WI into northern IL. Boundary layer
moisture is somewhat modest, mainly in the low 60s, but this should
increase some through the day within a low-level warm advection
regime. While cloudiness and isolated showers persist across
northern IL, this is expected to gradually shift eastward and erode. Regardless, instability should increase from west to east across
this area through the afternoon, aided by cool temperatures aloft.=20

Regional VWP and SPC Mesoanalysis indicate effective shear greater
than 35 kt overspreading the region. Furthermore, forecast soundings
show elongated/straight hodographs. This kinematic environment
should support both clusters and supercells, with an accompanying
risk of isolated large hail and severe/damaging wind gusts.
Low-level SRH is generally modest across the region, but may be
locally enhanced across the far southern WI/northern IL vicinity
near the lake breeze and perhaps differential heating zone. A
tornado or two could also occur across the area. A severe
thunderstorm watch may be needed for portions of the MCD area in the
next couple of hours.

..Leitman/Guyer.. 06/24/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!98p65cDPw2vL8bmFddN1CcUI84Sz-AKiZUlUBKIYe5BFyeNrQ_DvdbAcCayzUcg0ywdcUaXI_= lwYZ6Ws_ZNCcymhWDM$ for graphic product...

ATTN...WFO...IWX...GRB...LOT...MKX...DVN...DLH...ARX...MPX...

LAT...LON 45238856 44598800 43968758 41598651 41448656 41148677
40908732 41198882 41619010 42769102 44229159 44849159
45259127 45579096 45749030 45658934 45238856=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


=3D =3D =3D
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