ILLINOIS — Active severe weather is set to return to the Midwest on Monday, July 20, with a Level 1 marginal risk covering a broad swath of Illinois, Wisconsin, and Iowa. Forecasters say all severe weather modes will be possible, with straight line winds identified as the most likely hazard across the region.
The risk area stretches from southern Minnesota through Wisconsin and into northern Illinois, encompassing major cities including Chicago, Madison, Rochester, and portions of the Detroit metro area farther east.
Level 1 Marginal Risk Covers Broad Multi-State Area
The Level 1 marginal risk carries a 15 percent probability for severe weather Monday, extending across a large footprint from southern Minnesota and Sioux Falls through Wisconsin, Iowa, and into northern Illinois. This category represents the lowest tier on the severe weather outlook scale but still signals organized storm potential.
Chicago and Madison both fall within the outlined risk zone, along with Rochester and areas approaching the western Michigan border, indicating a wide-reaching system capable of impacting numerous communities across state lines.
Straight Line Winds Identified as Primary Concern
While all modes of severe weather remain possible Monday, forecasters emphasize that straight line winds are expected to be the most likely and widespread hazard. These winds can produce damage similar to tornadoes over a broader path when storms develop into organized clusters…