(11:45AM - 1/23/20) A major winter storm is expected to impact the state and region, Monday and Tuesday. This winter storm is expected to bring significant snowfall accumulation, as well as some ice and sleet accumulation, to portions of the state.
A major winter storm is expected to impact the state and region on Monday and Tuesday, and is expected to bring significant snowfall accumulation, as well as some ice and sleet accumulation, to portions of the state. The storm system will eject out into the Plains Sunday night and Monday, moving northeastward, and eventually into the Great Lakes on Tuesday as it slowly shears out and weakens. Model guidance has been showing the potential for this winter storm for days, though there was a high amount of disagreement regarding the overall potential. As time has gone on over the past day or so, model guidance has come into much better agreement, with a loose consensus forming.
Snow is expected to spread across Northern Illinois Monday morning. Snow of varying intensity will then continue through early Tuesday night. The most significant period of snow will be from late Monday afternoon through mid Tuesday morning. During this time periods of heavy snow will be possible, with high snowfall rates in excess of 1" an hour likely at times. In addition to the snow, wind gusts of 35-45MPH will be possible, Monday evening through Tuesday morning. The combination of the snow and wind will lead to near blizzard conditions at times, especially out towards the Quad Cities and IL/IA border area.
Precipitation will spread across Central Illinois later Sunday night and Monday morning. South of I-72 will generally see rain for the duration of the storm, though a mix is possible at times. Along and north of I-72 will generally see freezing rain and sleet for the duration of the storm.
Rain will spread into Southern Illinois Sunday night, and will then continue in periods through Tuesday morning. Isolated t'storms will be possible at times. Rainfall totals in excess of 1.00" is expected across Southern Illinois.
A swath of heavy snowfall totals of 6-12" is expected across Northern Illinois, with higher amounts possible near the IL/IA and further west. 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 0.10-0.25" is expected in an axis across Central Illinois.
Below are the snow and ice forecasts for this event.