Severe thunderstorm watch issued across US: See full list of counties at risk

More than 14 million people across four Midwestern states are at high risk, triggering thunderstorm watches for Monday, May 18.

The weather conditions are more likely to be a volatile mix of heat and humidity followed by damaging winds, large hail, and isolated tornadoes.

A severe thunderstorm watch has been issued by the National Weather Service spanning from southern Minnesota through Wisconsin and into Chicagoland and northwest Indiana.

The watch remains in effect until early evening, with some extending as late as 10:00 p.m. (local time).

As of Monday afternoon, major counties at risk include:

Illinois

The counties of Cook, Lake, Will, Grundy, and Kendall, among others, within the Chicago metropolitan area, continue to be under watch until 5 p.m. CDT. The Severe Thunderstorm Warning was issued for Cook and Lake counties earlier.

Indiana

Lake County, northwestern Indiana, is under watch within Chicagoland. On the other hand, all of Michiana, comprising St. Joseph, Elkhart, Kosciusko, Marshall, and LaPorte counties, continues to be under Severe Thunderstorm Watch until 6 p.m. EDT.

Wisconsin

Southeast Wisconsin counties, including Milwaukee, Waukesha, Jefferson, Racine, Kenosha, and Walworth, were also under thunderstorm watch through early Saturday morning. An additional warning is issued for Monday afternoon.

Minnesota

A tornado watch is issued for southwestern and southern Minnesota until 10:00 p.m. CDT, with escalated risk (level 3 of 5) for the south-central parts of the state. Between 9 and 11 p.m., a storm is expected to hit the Twin Cities and eastern Minnesota.

Major threats include wind gusts up to 70 mph, hail the size of ping pong balls, and isolated tornadoes.

Travel disruption is currently occurring. The FAA announced a ground stop at Midway Airport in Chicago and has indicated that there were an average of 76-minute delays for arrivals at O'Hare.

Over 4,200 schools and 278 hospitals are located within the watch zones.

There could be another round of storms on Tuesday before a quick chill brings temperatures down to around 60 degrees.