CHICAGO — A tornado outbreak that swept the Chicago area this week produced at least 11 twisters, and preliminary findings show they were relatively weak, the National Weather Service said Friday.
No injuries were reported when Wednesday’s storms ripped roofs from buildings and toppled trees in the Chicago area and points west. One tornado touched down near O’Hare International Airport, sending passengers dashing for shelter and disrupting hundreds of flights.
Weather service staff have confirmed that at least 11 tornadoes touched down Wednesday evening, the agency’s Chicago-area office said in an update. The twisters were spawned by rotating thunderstorms known as supercells, the weather service said.
Eight of the confirmed tornadoes had preliminary ratings of EF-0, which produce winds of 65-85 mph, while the three others had preliminary ratings of EF-1, which have winds of 86-110 mph, it said.
An outbreak this spring produced 22 tornadoes in Chicago’s expansive metro area.