A fast-moving storm with 99 mph winds raced through the Chicago area on Tuesday, leaving a path of destruction in the south suburbs and northwest Indiana, delaying hundreds of flights and cutting power to hundreds of thousands.
It was too early to say if tornadoes touched down in far southern Cook County and northern Will County, where survey teams with the National Weather Service were focusing their damage assessments.
The crews were checking for possible tornadoes near Homer Glen, Tinley Park, Crete and Manhattan, as well as in parts of northwest Indiana.
Tornado and thunderstorm warnings expired early in the afternoon, after around 1 or 2 inches of rain likely fell, National Weather Service meteorologist Scott Baker said.
The Gary/Chicago International Airport reported wind gust of 99 mph around 11 a.m. There were reports of 81 mph winds in South Barrington, and 70 mph in Oak Lawn.
The strongest squalls erupted through a “kind of a corridor,’’ south and southwest throughout Cook County and adjacent collar counties, Baker said.
Damage was reported across the Chicago region.
Power lines fell into the roadway on 175th Street in Tinley Park and on Kedzie Avenue in Flossmoor, according to Cook County emergency alerts.
People on social media posted photos of downed trees in Gary and Munster, Indiana, and several south and southwest suburbs.
About 357,000 ComEd customers were affected by the weather, said a ComEd spokesman. By 3:30 p.m., the number of outages was down to 250,000.
The storms also wreaked havoc on air travel.
Nearly 300 flights were canceled at O’Hare Airport, according to FlyChicago.com. At Midway Airport conditions were less severe, with only a handful of cancellations.
In northwest Indiana, Portage Township canceled the first day of classes on Wednesday due to the damage. Portage Mayor Austin Bonta wrote on social media that the damage from the storm was extensive.
“I just spoke with our Chief of Police. He has never seen so much destruction in one storm as we’ve gotten so far in this one. Several roads are impassable across the city,” Bonta said on Facebook.
Ald. Raymond Lopez (15th) posted photos of several downed trees in his ward that covers the Southwest Side.
Some examples of the unreported tree emergencies we found in the 15th Ward! pic.twitter.com/7SWjEJlB0c
— Ald. Raymond Lopez (@RaymondALopez) August 11, 2026
A lakeshore flood advisory, including for the southern half of Cook County, was in effect until 5 p.m. Tuesday.
The storms were expected to give way to cooler temperatures and a chance of light showers before the high rises to the 80s on Wednesday.
Late last month, several storms ravaged the area, leaving neighborhoods in the south suburbs picking up the pieces after seven tornadoes touched down — damaging homes, uprooting trees and adding to what has already been an active tornado season in Illinois.
“We’re in a real unsettled weather pattern now,” Baker said. “It’s just wet and humid and everybody’s like, ‘OK, we’re done with this.'”
