Storm Prediction Center Mesoscale Discussion 1490

   Mesoscale Discussion 1490
   NWS Storm Prediction Center Norman OK
   1124 AM CDT Sat Jul 04 2026

   Areas affected...north-central Illinois into Indiana

   Concerning...Severe potential...Watch possible 

   Valid 041624Z - 041930Z

   Probability of Watch Issuance...60 percent

   SUMMARY...A cluster of strong to severe storms is expected to
   develop after 18Z over central and north-central Illinois, moving
   into Indiana later this afternoon. Damaging gusts will be possible.

   DISCUSSION...Visible satellite and surface observations show a low
   and MCV moving out of eastern IA into northern IL. Analyzed
   streamlines show substantial convergence into northwest IL
   currently, with modest southerly winds ahead of this feature aiding
   warming/destabilization. Cooler air exists over southeast WI and
   northeast IL, but areas of heating and gradual warm advection may
   allow destabilization close to parts of the Chicago metro area.

   The 12Z ILX sounding shows high PWAT over 1.75", along with 25-35 kt
   midlevel westerlies. Overall storm motions will be toward the east,
   with a tendency for southeastward propagation. This could bring wind
   potential toward the Indianapolis area during the early evening.

   ..Jewell/Hart.. 07/04/2026

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

   ATTN...WFO...IWX...IND...LOT...ILX...DVN...

   LAT...LON   40118965 40489010 41258940 41948909 41818777 41698682
               40928653 40398654 39788684 39608762 39618768 40118965 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN