Showers are advancing into the Chicago area from the west this afternoon. The rain will be light at the onset, but with copious amounts of moisture available, rainfall could become heavy later this evening and overnight with 1 to 3-inch rainfall totals possible. Thunderstorm development is also expected and the storms could become severe, especially south of the city.
The greatest threat of severe weather will be along and south of Interstate 80.
Much of Illinois is in an area that could receive heavy rainfall overnight. With 1 to 3-inch rainfall totals expected, some local flooding could occur.