Credit: Tanveer Ali / DNAinfo

CHICAGO — A severe thunderstorm that could cause significant damage with wind gusts up to 100 mph is expected to hit Chicago on Monday afternoon.

The day will start humid and could feel as warm as 97 degrees late in the morning and in the afternoon, according to a hazardous weather outlook for the National Weather Service.

That heat will give way to a “pretty significant” line of thunderstorms that are already sweeping across the Midwest, said Brian Leatherwood, a National Weather Service meteorologist. The storms have been severe so far, causing “quite a bit of damage” in Iowa, Leatherwood said.

The storms could have wind gusts up to 100 mph and large hail, with the potential for “a tornado or two” forming throughout the Chicago area, Leatherwood said.

The National Weather Service warned hail could be the size of ping pong balls, there could be flooding, there could be power outages and the strong winds could take down trees.

“A particularly dangerous situation has developed with severe storms moving in to” northern Illinois and Indiana, the National Weather Service said in a tweet.

In another tweet, the agency said people who receive a warning for the storm should “treat it like a tornado warning. Head for safe shelter indoors, well away from windows … .” People should try to be in a windowless room or basement, if possible.

People should take steps to prepare for the weather, like securing or even bringing inside lawn furniture, Leatherwood said.

That’s a “very smart idea if possible, just to avoid things becoming airborne objects, increasing damage or even injuring somebody,” Leatherwood said.

The storms will start mainly after 5 p.m. and could last throughout the night, though there’s also a chance for rain earlier in the day, according to the National Weather Service.

The storms will move toward the east and southeast at 40-50 mph, according to the National Weather Service.

There’s a limited risk of thunderstorms Tuesday morning, as well.

Subscribe to Block Club Chicago. Every dime we make funds reporting from Chicago’s neighborhoods.

Already subscribe? Click here to support Block Club with a tax-deductible donation.

kelly@blockclubchi.orgnnkelly@blockclubchi.org Twitter @BauerJournalism