Scientists with the National Weather Service confirmed that a tornado touched down Monday in Lake County and went over the state line before ending over a lake in southeastern Wisconsin.
According to NWS officials, the tornado, classified as an EF-1 rated twister, reached estimated peak wind speeds of 90 miles per hour after it touched down at approximately 3:41 p.m. Monday near Spring Grove, Illinois.
The tornado was on the ground for approximately 3.75 miles before ending near Camp Lake, Wisconsin.
The tornado’s maximum width was approximately 150 yards, according to a damage path surveyed by NWS Chicago and Milwaukee researchers.
According to officials, the tornado was one of several reported during Monday’s derecho, which packed dangerously gusty winds and torrential downpours. The storms prompted tornado warnings across the area, including in Lake County and Kenosha County, and left hundreds of thousands of customers without electricity.
Another tornado was confirmed in Chicago’s Rogers Park neighborhood at approximately 3:59 p.m. Monday. That tornado packed wind speeds of up to 110 miles per hour, and traveled for approximately three miles before moving onto Lake Michigan and becoming a waterspout.