The entire area was under a Level 2 risk for severe weather, and some southwestern counties were under a Level 3 risk, ABC7 Chicago meteorologist Tracy Butler said.
The storms spurred Severe Thunderstorm Watches and Warnings throughout the area.
Some storms moved through Thursday morning and afternoon, ABC7 Chicago meteorologist Larry Mowry said, causing hail, high winds and heavy downpours at times.
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A round of storms formed a line from Cook County to the DuPage County area, and moved through Thursday afternoon, spurring some Severe Thunderstorm Warnings in northwest Indiana and Kankakee County, Mowry said.
Another round of storms sparked warnings mainly south of Interstate 80.
It was muggy and hot Thursday ahead of the storms.
As a first line of storms developed in the far north suburbs on Thursday morning, the Federal Aviation Administration issued a ground stop for arriving flights at O'Hare and Midway for about two hours; both were canceled by 8:30 a.m.
The National Weather Service confirmed a microburst happened on Thursday morning in Carol Stream.
Microburst confirmed in Carol Stream: NWS
Friday and Saturday should be pleasant, but next week will have intense heat.