Round 2 of the winter storm will quickly develop Tuesday morning, especially by the mid to late morning hours. The focus for heavy, wet snow, and significantly impacted travel will shift to areas northwest of I-55/94 with a transition to rain to the east and southeast. A very sharp gradient in snowfall amounts will occur in the vicinity of the rain/snow line, which includes the city of Chicago and parts of the Illinois North Shore. Small changes in the rain snow line on Tuesday may cause noteworthy changes in the snowfall amounts. Plan for a difficult Tuesday evening commute.