Forecasters also warned that another storm system was expected in the Chicago area Wednesday night and Thursday morning, although meteorologists said it was too early to say how much snow may fall and which areas should expect the greatest accumulation. One social media post suggested the rate of snowfall Wednesday into Thursday could reach half-an-inch per hour. The thickest snowfall was expected at night Wednesday. A large part of the Chicago area, including all of Cook, DuPage and Kendall counties, as well as much of Will, Lake and Kane counties, according to the weather service.