(11:45AM - 1/25/20) A winter storm is impacting the state and region, today through Tuesday. This winter storm is expected to bring accumulating snow, sleet and ice to portions of the state.
A winter storm is impacting the state and region today through Tuesday, and is expected to bring accumulating snow, ice and sleet to portions of the state. The storm system ejected out into the Plains last night, and is expected to push eastward into the Great Lakes through Tuesday...as it slowly shears out and weakens, encountering blocking to the northeast. Model guidance has had a tough time getting a handle on this event, even as it has been ongoing to our west across the Plains today. A drying trend on model guidance was noted over the past 24-36 hours, which lead to us cutting snowfall total a bit across Northern Illinois. However, several inches of snowfall accumulation is still expected.
Snow is expected to spread across Northern Illinois mid to late afternoon today. Snow of varying intensity will then continue through Tuesday afternoon, except in Northeast Illinois where periods of lake effect snow will continue into Wednesday. The most significant period of snow will be from late this afternoon through early Tuesday morning. During this time periods of moderate to even heavy snow will be possible, with snowfall rates in excess of 1" an hour possible at times. In addition to the snow, wind gusts of 30-40MPH will be possible, this afternoon through Tuesday morning. The combination of the snow and wind will lead to very low visibility and blowing/drifting snow at times, especially out towards the Quad Cities and the IL/IA border area and in Northeast Illinois near Lake Michigan.
As hinted at in the above paragraph, lake effect snow was mentioned for Northeast Illinois. It is likely that that lake enhanced snow will be seen during the storm, from this afternoon through Tuesday afternoon...After which time periods of pure lake effect will be possible from Tuesday afternoon through Wednesday morning.
An initial area of precipitation spread across Central Illinois this morning, then continuing, in the for of a mix of snow/sleet/freezing rain. This area of mix will exit Central Illinois by early afternoon, leading to a period of generally dry conditions during the afternoon int he dry slot of the storm system. Precipitation will start to develop and spread back into Central Illinois during the mid to late afternoon today, then continuing in periods through Tuesday morning. South of I-72 will generally see rain for the duration of the event, though a mix is possible at times. Near/along and north of I-72 will see a mix of snow/sleet/freezing rain/rain, though freezing rain is expected to dominate in a corridor across Central Illinois.
Rain spread into Southern Illinois last night and has been heavy at times, with scattered t'storms occurring as well. The most organized and widespread rains will continue through this afternoon, before ending. Afterwards, periods of scattered showers will then be possible from this afternoon through Tuesday morning. Rainfall totals in excess of 1.00" are expected across far Southern Illinois.
A swath of heavy snowfall totals of 5-9" is expected across Northern Illinois, with isolated higher amounts possible. There will be a sharp gradient where snowfall totals rapidly taper across across Western Illinois and along I-80 in Northern Illinois. Ice accumulation upwards of a glaze to 0.15" is expected in an axis across Central Illinois.
Below are the snow and ice forecasts for this event.