A line of storms brought heavy rain, flashes of lightning, and pounding thunder to the Chicago metropolitan area early Monday morning. In southern Wisconsin, significant damage was caused by one confirmed tornado.
A Tornado Watch was issued late Sunday night for several counties including Boone, McHenry, DeKalb, Kane, Lee, Ogle, Winnebago, Whiteside, and Stephenson. That watch remained in effect until 4 a.m. Monday.
The National Weather Service reported a funnel cloud in Crystal Lake, in McHenry County, at about 2:15 a.m. but there was no confirmation of a touchdown. Visible storm damage in Crystal Lake included matted crops, several blown trees and a house fire attributed to a lightning strike.
Radar reported a strong storm cell in Wauconda at about 2:40 a.m. That cell was in Waukegan by 3:15 a.m. By 5 a.m., the strongest storms were in the Streator and Kankakee area, south of Chicago. They were moving eastward toward northwest Indiana.
At least one twister was confirmed to have touched down in Spring Green, Wisconsin. Video from one neighborhood showed pieces of an outdoor deck were blown into the upstairs window of a home. Eleven counties in southern Wisconsin were under a tornado watch all night long.