Northern IL to SE Wisconsin Thunderstorms Charge Up for Gusts, Hail — SevereWX

Thunderstorms are showing signs of strengthening across portions of northern Illinois into southeast Wisconsin, where a watch could be issued soon.

The SPC's Mesoscale Discussion 1465 highlights isolated storms moving through northern IL and far southern WI at midday, with gusts so far topping out around 30-35 mph. But downstream conditions are ripe for escalation: mid-80s temperatures, mid/upper 70s dewpoints, and modest midlevel lapse rates are driving moderate to strong destabilization.

Peak hazards include wind gusts of 55-70 mph and hail up to 1.25 inches. Visible satellite imagery reveals growing cumulus along outflow boundaries and in the warm sector, hinting at broader coverage into early afternoon.

Uncertainty persists from limited large-scale ascent and modest vertical shear—stronger flow stays just north of the prime instability axis. Still, SPC pegs watch odds at 40% and will monitor trends closely.

This setup impacts areas from near Rockford, IL, northeast toward Milwaukee, WI, during a busy holiday period. Keep radar handy as activity peaks.

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