(11:00PM - 12/26/21) A storm system is expected to move through the region on Tuesday. This storm system will have to potential to produce a period of accumulating snow across Northern Illinois.
A storm system will move from the Plains Tuesday morning, into the Northern Great Lakes by Tuesday night. This storm system will have the potential to produce a period of accumulating snow across Northern Illinois, Tuesday morning through Tuesday afternoon, before precipitation changes to rain and/or ends. There is still uncertainty and model disagreement regarding this potential. Stay tuned for future updates.
Precipitation is expected to spread into Central Illinois early Tuesday morning, in the form of rain. As precipitation pushes northeastward into Northern Illinois Tuesday morning, it will work into colder air, allowing for a transition to snow. Snow will be possible across Northern Illinois for a several our period of time, from Tuesday morning through Tuesday afternoon. As milder air works northward and the back-edge of the precipitation shield moves in, snow will change over to rain and end, later Tuesday afternoon and evening. It is looking increasingly likely that there will be the potential for minor snowfall accumulation across a large portion of Northern Illinois with this event.