Overview
- The Storm Prediction Center upgraded the region's short‑term severe threat from level 1 to level 2 for the Chicago area, expanding the heightened outlook to include Cook County and parts of northwest Indiana.
- A severe thunderstorm watch covers multiple counties until 10 p.m., with watches named for Lake, McHenry, Kane, Kendall, Grundy, DeKalb, LaSalle in Illinois and Kenosha in Wisconsin.
- Forecasts call for two main waves of storms late Wednesday, roughly in the late afternoon and again in the late evening with a brief lull between the rounds.
- The National Weather Service warns storms could produce damaging straight‑line winds near 60 mph, quarter‑size hail, frequent lightning and heavy downpours, and an isolated tornado cannot be ruled out.
- Forecasters caution the recent early‑June derecho‑style outbreak and saturated soils raise the risk of stronger runoff and power‑outage impacts, and they note a major heat wave with highs above 90°F and heat indices over 100°F is expected in the Fourth‑of‑July week.