NWS Chicago, IL
A cold front is advancing across the region late this evening and will continue to move southeastward overnight. Warm and very humid conditions have persisted in advance of the front. Isolated to scattered thunderstorms will continue until overnight hours. Given how warm and humid it is, if a storm does develop it could become strong to severe as well as be accompanied with torrential downpours. Overall the coverage of storms appears low.
Also see the Weather Story of the day.