(5:30PM - 1/5/21) A brief recap regarding the Fri, January 1st winter storm that affected portions of the state with snowfall and significant ice accumulation.
A storm system is ejected out from the Southern Plains/Gulf Coast Thursday night (Dec. 31st), tracking northeastward through the Ohio Valley on Friday (Jan. 1st), and into the Eastern Great Lakes by Saturday (Jan. 2nd). A large shield of precipitation spread across the state, Thursday night through late Friday night. Precipitation ranged from snow/sleet and ice across Northern Illinois, to ice and rain across Central Illinois, to rain across Southern Illinois.
A mix of freezing rain, sleet and snow spread into Northern Illinois, mid to late Friday morning. A freezing rain, sleet and snow mix then occurred across Northern Illinois from late Friday morning through late Friday afternoon. As colder air filtered in, the mix transitioned to snow across much of Northern Illinois Friday evening. Snow then continued into Friday night, before ending.
Thursday night precipitation in Southern Illinois spread northward into Central Illinois. With colder air in place, precipitation was in the form of freezing rain. Freezing rain then occurred across Central Illinois from Thursday night through late Friday morning. As the storm system passed, precipitation turned to snow Friday afternoon and evening, eventually ending early Friday night.
A mix of rain and freezing rain spread into Southern Illinois early Thursday night. This mix turned rain overnight, with periods of rain will then continuing through Friday evening, before ending.
Final snow/sleet totals upwards of 1-3" occurred across a good portion of Northern and Central Illinois. Widespread significant ice accumulation of 0.10-0.50"+ occurred across a large portion of Northern, Central and Southwest Illinois. Wind gusts of 20-35MPH, combined with the ice accumulations, lead to widespread tree damage and power outages for some of the affected areas.
Below are map representations of final forecasts an observed snowfall and ice totals across the state and adjacent areas.