(10:15PM - 2/13/21) A winter storm is expected to affect the region Sunday through Tuesday, bringing waves of accumulating snow to portions of the state. Additionally, lake effect snow will be possible across Northeast Illinois.
A storm system is expected to affect the region Sunday through Tuesday, with an extended period featuring waves of accumulating snow for portions of the state. The storm system will eject out from the Gulf of Mexico and into the Southeastern US, Sunday and into Monday. The storm system will then move northeastward through the Mid-Atlantic on Tuesday. Model guidance continues to come into better agreement as time goes on regarding aspects of this winter storm. As better agreement occurs and confidence increases, snowfall totals have been increased a bit for some areas, as well as a slight adjustment to the placement of the wide snowfall axis.
A lengthy period featuring waves of accumulating snow will affect a large portion of the state, from Sunday morning through Tuesday morning. During this time 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, with snowfall rates in excess of 1" an hour at times...Especially across Southern and portions of East-Central Illinois.
In addition to the synoptic snow, across Northeast Illinois lake enhanced snow is possible during the event and lake effect snow is expected after the event ends. This is expected to lead to lake boosted snowfall accumulations across Northeast Illinois. Periods of moderate to heavy snow, with snowfall rates of 1-2" an hour, can be expected at times near the lake shore (Cook Co).
Final snowfall totals upwards of 4-7" are expected across the southern half of the state, with locally higher amount possible. Across Central Illinois, snowfall totals will taper, with 1-5" being likely. Across Northeast Illinois where lake effect/enhancement is expected, snowfall totals of 4-9" are expected near the immediate lake shore (Cook Co), and 1-5" further inland.
Below is the snowfall forecast for this event.