(11:45AM - 2/14/21) A snowstorm is expected to affect the region today through Tuesday, bringing waves of accumulating snow to the state. Additionally, significant lake effect/enhanced snow is expected across Northeast Illinois.
A storm system will be impacting the region today through Tuesday, with an extended period featuring waves of accumulating snow for the state. The storm system will eject out from the Gulf of Mexico and into the Southeastern US, today and into Monday. The storm system will then move northeastward through the Appalachians on Tuesday. Model guidance from overnight and this morning has taken a shift northwest. This shift means the entire state is now expected to see an accumulating snowfall, with an increase in expected snowfall totals for a large area as well. With this update we have taken into account the shift in our forecast, with the aforementioned changes.
A lengthy period featuring waves of accumulating snow will affect the state, from this morning through Tuesday morning. Two more distinct periods of snow look to impact the state...One from this morning through Monday morning, and the second from Monday morning through Tuesday morning. The second period will feature the most organized and widespread snow, in addition to the heaviest snow and most snowfall accumulation. During this entire snowstorm period (Sun morning-Tue morning) snow will be of varying intensity, with a few breaks between periods/waves of snowfall being possible. Snow will be moderate to heavy at times, especially during the second period of snow Monday morning through Tuesday morning. During this time snowfall rates in excess of 1" an hour will be likely at times, especially across Central, Southern and Northeast Illinois.
In addition to the synoptic snow, across Northeast Illinois lake enhanced snow is likely during the snowstorm and lake effect snow is likely after the snowstorm ends. This is expected to lead to lake boosted significant snowfall accumulations across portions of Northeast Illinois. Periods of moderate to heavy snow, with snowfall rates of 1-3" an hour, can be expected across counties near the lake.
Final snowfall totals upwards of 4-9" are expected across Southern Illinois and a large portion of Central Illinois. Across Western, Northwest and North-Central Illinois...Totals will taper with northwest extent. Across Northeast Illinois where lake effect/enhancement is expected, snowfall totals of 6-12" are expected for counties near Lake Michigan.
Below is the snowfall forecast for this event.