459
ACUS11 KWNS 271253
SWOMCD
SPC MCD 271252
INZ000-MIZ000-ILZ000-271445-

Mesoscale Discussion 1759
NWS Storm Prediction Center Norman OK
0752 AM CDT Mon Jul 27 2026

Areas affected...Northeast Illinois into Northern Indiana and
southwest lower Michigan

Concerning...Severe potential...Watch possible

Valid 271252Z - 271445Z

Probability of Watch Issuance...40 percent

SUMMARY...A watch is possible this morning for the lower Lake
Michigan vicinity, though uncertainty remains high. Convective
trends will need to be monitored this morning.

DISCUSSION...Current radar CAPPI trends suggest that the storm
ongoing in southwest lower Michigan has trended down in intensity
over the past 30 minutes. That said, model guidance such as the RRFS
and HRRR continue to highlight the southern Lake Michigan vicinity
as an area for possible development/intensification later this
morning. Objective mesoanalysis shows strong to extreme buoyancy
across northern Illinois into parts of northern Indiana. Morning
observed soundings from the region show similar MLCAPE values as
well as steep mid-level lapse rates and strong shear. Forcing for
ascent will be nebulous and cloud cover/capping also limits
confidence on where, or if, additional severe storms will develop
later this morning. However, visible satellite trends show areas of
convective turrets from northeast Illinois into southern Lake
Michigan. This area will need to be monitored for a possible watch
though uncertainty in this scenario is admittedly high.

..Wendt/Guyer.. 07/27/2026

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

ATTN...WFO...IWX...GRR...IND...LOT...

LAT...LON   40448579 40598638 40978710 41438793 41948832 42408822
            42448756 41988510 40928484 40318528 40448579

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN