Tue-Wed, Dec 29-30th Snow Event

​(11:45PM - 12/27/20) A storm system will move through the region Tuesday and Wednesday, bringing the chance for accumulating snow to portions of Northern Illinois and a wintry mix to portions of Northern and Central Illinois, Tuesday afternoon through Wednesday afternoon.

Summary...
A storm system will move through the region Tuesday and Wednesday, bringing the chance for accumulating snow to portions of Northern Illinois and a wintry mix to portions of Northern and Central Illinois, Tuesday afternoon through Wednesday afternoon. There has been a select few within model guidance that have been consistent with many aspects of this event, while other model guidance has been much further north with placement...But much of this guidance has been trending towards the aforementioned consistent guidance with time. A weak and loosely organized storm system is expected to eject out from the Plains on Tuesday, tracking northeastward, and into the Great Lakes on Wednesday. With cold air in place, snow will generally be favored across far Northern portions of Northern Illinois, with more of a wintry mix likely across other portions of Northern Illinois and also portions of Central Illinois for a time.

​Forecast...
A large area of precipitation is expected to spread across the state, from Tuesday afternoon through Wednesday afternoon. Precipitation will first push into Northwest and Western Illinois Tuesday afternoon and evening, in the form of snow across Northwest Illinois and a wintry mix (snow/sleet/freezing rain/rain) across Western Illinois. As precipitation spreads further across Northern and Central Illinois Tuesday night, much of it will fall as snow across a good portion of Northern Illinois and a wintry mix to rain across Central Illinois. By Wednesday morning as warm air advection continues, the wintry mix across portions of Central Illinois will have turned to all rain, and snow across portions of Northern Illinois will have turned to a wintry mix. Only far Northern Illinois will likely remain as all snow. By later Wednesday morning and afternoon, precipitation across Northern and Central Illinois will end from west to east.

Final snowfall totals in the main axis will generally range from 3-6", with totals rapidly lowering along the southern end of the axis. Additionally, some sleet and ice accumulation will be possible as well across Northern Illinois.

​Below is the snowfall forecast for this event.

JP