A Chicago Tornado warning swept across part of the region Tuesday morning, sending office workers to shelter and briefly disrupting air travel as severe storms moved through Illinois and Indiana. By late morning, multiple counties were under Tornado Warnings, Severe Thunderstorm Warnings and flood alerts at the same time.
Chicago office workers were told around 10:45 a.m. to take shelter as the weather threat tightened over the city. The warning for Cook and DuPage counties ran until 11:15 a.m., while other Tornado Warnings covered Grundy, Kankakee, Kendall and Will counties until 11:30 a.m. and Lake and Porter counties in Indiana until 11:45 a.m.
The alerts were not limited to tornado risk. A Severe Thunderstorm Watch remained in effect for the Chicago area until 2 p.m., and separate warnings covered Cook, DuPage, Kane and Kendall counties in Illinois, as well as LaPorte County in Indiana. Another Severe Thunderstorm Warning covered Kankakee and Will counties in Illinois and Lake and Newton counties in Indiana until 11:45 a.m., while flood alerts stretched from LaPorte County to Cook, DuPage, Kankakee, Will, DeKalb, LaSalle, Grundy, Kane and Kendall counties.
The weather system also reached the airports. A Ground Stop at Midway and O'Hare airports lasted until about 11:30 a.m., and around 11 a.m. there were about 200 flight canceled at O'Hare. That kind of disruption usually follows fast-moving storms that force controllers and airlines to pause traffic while lightning, wind and low visibility pass through the area.
What the alerts did not say was whether a tornado actually touched down anywhere in the warned counties. The warnings were real and immediate, but they remained warnings and watches in the information available Tuesday, with no confirmed touchdown included in the reports.
For Chicago and the surrounding counties, the day turned on a narrow window of late-morning weather and the next few hours of storm movement. More powerful winds were still in the forecast, and the question left hanging was not whether people had been warned, but whether the damage stayed with the alerts or moved beyond them.
