Severe storms, possible tornadoes cause damage across northern Illinois

A rare storm packing 100 mph winds with power similar to an inland hurricane swept across the Midwest on Monday, blowing over trees, flipping vehicles, causing widespread property damage and leaving hundreds of thousands without power as it moved through Chicago and into Indiana and Michigan.

The storm, known as a derecho, lasted several hours as it tore from eastern Nebraska across Iowa and parts of Wisconsin and Illinois, had the wind speed of a major hurricane, and likely caused more widespread damage than a normal tornado, said Patrick Marsh, science support chief at the National Weather Service’s Storm Prediction Center in Norman, Oklahoma.

In northern Illinois, the National Weather Service reported a wind gust of 92 mph near Dixon, about 100 miles west of Chicago, and the storm left downed trees and power lines that blocked roadways in Chicago and its suburbs. After leaving Chicago, the most potent part of the storm system moved over north central Indiana by late afternoon.

“The storm system as a whole is definitely beginning its decay,” said Northern Illinois University meteorology professor Victor Gensini.

The severe weather threat exited the northern Illinois area by 4:30 p.m., but not before causing significant property and tree damage throughout the region. Strong winds persisted into the early evening. The National Weather Service canceled its high wind warning at 6:03 p.m.

According to the weather service, a derecho is a storm line that extends at least 240 miles and has wind gusts of at least 58 miles per hour or greater.

As of 6:20 p.m., ComEd reported 462,217 customers throughout the region were affected by power outages.

Widespread damage was reported in La Salle and Bureau counties. Motorists were trapped near the Matthiessen State Park entrance by a fallen tree.

At about 4:20 p.m., the McHenry County Sheriff's office said on social media that it is responding to trees and power lines downed across roadways throughout the county. The Lake County Sheriff's office reported that multiple roadways in the county are impassable.

In Kendall County, power lines and tree limbs were reported down at Van Emmon Street and Route 47 in downtown Yorkville and along Hampton Road in the unincorporated Boulder Hill subdivision.

A derecho is not quite a hurricane. It has no eye and its winds come across in a line. But the damage it is likely to do spread over such a large area is more like an inland hurricane than a quick more powerful tornado, Marsh said. He compared it to a devastating Super Derecho of 2009, which was one of the strongest on record traveled more than 1,000 miles in 24 hours, causing $500 million in damage, widespread power outages and killing a handful of people.

“This is our version of a hurricane,” Northern Illinois University meteorology professor Victor Gensini said in an interview from his home about 15 minutes before the storm was about to hit.

Minutes later he headed to his basement for safety as the storm took aim. Gensini said this derecho will go down as one of the strongest in recent history and be one of the nation's worst weather events of 2020.

This story will be updated as more details become available. The Associated Press contributed to this story.