http://www.chicagotribune.com/news/l...,3131638.story
The area at risk includes the entire city of Chicago and notably Soldier Field, where the Bears are scheduled to play the Baltimore Ravens at noon, right about the time the storms should be at their worst.
Beyond the tornado watch, the weather service's outlook for the region includes thunderstorms with occasional wind gusts as high as 75 m.p.h., hail the size of quarters, and the tornadoes, some of which could be "strong and long lived."