Storm Prediction Center Mesoscale Discussion 1292

   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 

   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. 

   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 www.spc.noaa.gov 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 

   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