A tornado warning was issued in northwest Indiana and most Chicago-area counties saw severe thunderstorm warnings on an eventful Sunday afternoon.

The Chicago area could see strong-to-severe thunderstorms on Sunday, with isolated tornadoes and damaging winds possible.

A tornado watch was issued Sunday afternoon until 7 ... The severe weather was expected to hit the Chicago metropolitan area between 1 and 4 p.m., said meteorologist Brett Borchardt of NWS Chicago.

The Storm Prediction Center has areas southeast of I-55 in an "Enhanced Risk," this is a level 3 of 5 on their severe risk scale. Locations near and along I-55 are in a "Slight Risk" (level 2 of 5), and then north and northwest portions of Chicagoland are in a "Marginal Risk" (level 1/5).

The Chicago branch of the National Weather Service tweeted out: "The potential for severe weather returns as early as Tuesday night (threat level 1 and 2 of 5) as multiple waves of storms life across the area, mainly after midnight. Large hail, gusty winds and lightning are the main hazards of the storm."

National Weather Service weather balloon releases — tracking temperature, pressure and wind speed — have been temporarily suspended in Omaha, Nebraska, and Rapid City, South Dakota, because of staff shortages and reduced at six other sites in the Midwest and Great Plains, according to agency memos.

Millions of people are under tornado watches across the central United States on Sunday, as a volatile weather system has triggered power outages and huge hail. Nearly 175 million people from Illinois to eastern Texas and beyond could be affected,