Despite Monday's seasonably mild temperatures, a major wintry dose is expected to sock the Chicago area Tuesday.
A strong low pressure system from the Southern Plains is forecast to move though the Ohio Valley to the lower Great Lakes on a historically favorable track to bring the city a significant snowfall.
Clouds roll in Monday night as gusty winds increase, setting the stage for the onset of wintry precipitation early Tuesday.
Precipitation may start as a wintry mix of rain, sleet or snow, but it is expected to transition to all snow by afternoon or evening as temperatures cool.
Snow accumulations will hinge how quickly the transition to snow occurs, but the potential exists for the city's biggest snowfall of the season.