The Chicago area experienced its largest snow of this relatively snow-free season on Sunday night and Monday. Patchy snow was still falling across the area Monday night with snow totals generally around three inches as of 8 pm, although some locations reported amounts up to 5 1/2 inches. An additional one to three inches of snow is possible into Tuesday.
An upper level storm system—a closed upper low—remains in the northern Illinois area into Tuesday, then “opens up” into a north-south oriented low pressure trough that slowly moves off to the east Wednesday. The presence of the closed low aloft (at and above 15 thousand feet) and cold air at the surface means periods of light snow will continue into Tuesday. In addition, heavy lake-effect snow continues into Wednesday across portions of northwest Indiana.