The Brief Showers and thunderstorms will spread across the Chicago area Friday afternoon, bringing periods of heavy rain into Saturday. Some locations could pick up at least 2 inches of rain, raising the risk of flooding. Chicago heavy rain and flooding threatShowers and thunderstorms will move into our area from west to east Friday afternoon. Ahead of the rain, we will make it into the low 80s this morning, then fall into the 70s once the rain begins. The potential exists for at least 2 inches of rain in some spots and flooding could be a concern.