Tornado watch until midnight as severe storms move through

The National Weather Service has issued a tornado watch for northern Illinois, including the suburbs, in effect until midnight tonight.

Cook, DuPage, Kane, McHenry, Lake, Boone, Ogle, DeKalb and Winnebago counties are included in the watch.

A tornado watch means conditions are favorable for tornadoes, not that any have been seen.

The watch is part of what the service is calling a severe storm system coming from Iowa and Wisconsin. The service said severe thunderstorms are likely this evening.

"The main threats are large hail, damaging winds, frequent lightning, and torrential rain that may lead to localized flooding," the service says on its website.

A flash flood watch is in effect until 6 a.m. Thursday for Cook, DuPage, Kane, McHenry, Lake, Boone, Lee, Ogle, DeKalb and Winnebago counties.

A chance of thunderstorms continues into Thursday, with a forecast high of 85 degrees.