A powerful cold front is expected to bring severe thunderstorms to northern Illinois after temperatures reach the 70s. The storms are expected to hit the Chicago area around 4 or 5 p.m., with some potentially continuing to the evening. There is also potential for supercells near Kankakee, which could develop with a tornado, hail, and wind threat. This comes after a series of tornadoes that ravaged the region two weeks ago.