(1:30PM - 2/1/21) A brief recap regarding the Mon-Tue, January 25-26th winter storm that affected portions of the state with snowfall and ice accumulation.
A winter storm impacted the state and region Monday through Tuesday (Jan 25-26th), bringing accumulating snow and ice to portions of the state. The storm system ejected out into the Plains Sunday night (Jan 24th), and then pushed eastward into the Great Lakes through Tuesday (Jan 26th)...as it slowly sheared out and weakened, encountering blocking to the northeast. Model guidance overall struggled significantly with this storm system, with the track, strength and precipitation/snowfall amounts. These struggled even occurred in the near term leading up to the storm, which made for a difficult forecast.
Snow spread across Northern Illinois mid to late afternoon on Monday. Snow of varying intensity then continued through Tuesday afternoon, except in Northeast Illinois where periods of lake effect snow continued into Wednesday. The most significant period of snow occurred from late Monday afternoon through early Tuesday morning. During this time periods of moderate heavy snow occurred, with some occurrences of snowfall rates in excess of 1" an hour. In addition to the snow, wind gusts of 25-40MPH occurred, Monday afternoon through Tuesday morning. The combination of the snow and wind will lead to periods of low visibility and blowing/drifting snow at times.
As hinted at in the above paragraph, lake effect snow was mentioned for Northeast Illinois. Lake enhanced occurred during the storm, from Monday afternoon through Tuesday afternoon...After which time periods of pure lake effect occurred from Tuesday afternoon through Wednesday morning.
An initial area of precipitation spread across Central Illinois Monday morning in the form of a mix of snow/sleet/freezing rain. This area of mix exited Central Illinois by early afternoon, leading to a period of generally dry conditions during Monday afternoon in the dry slot of the storm system. Precipitation then developed and spread back into Central Illinois during the mid to late afternoon on Monday, then continued in periods through Tuesday morning. South of I-72 generally saw rain for the duration of the event, though a mix did occur at times. Near/along and north of I-72 saw mix of snow/sleet/freezing rain/rain, though freezing rain was the dominate precipitation type in a corridor across Central Illinois.
Rain spread into Southern Illinois Sunday night and was heavy at times, with scattered t'storms occurring as well. The most organized and widespread rains then continued through Monday afternoon, before ending. Afterwards, periods of scattered showers occurred from Monday afternoon through Tuesday morning. Rainfall totals in excess of 1.00" occurred across Southern Illinois.
Final snow/sleet totals upwards of 4-7" occurred across a good portion of Northern Illinois, generally along and north of I-88...With snowfall totals rapdily tapering wouth southward extent south of I-88. Minor ice accumulation of a glaze to 0.15" occurred across portions of Northern and Central Illinois.
Below are map representations of final forecasts an observed snowfall and ice totals across the state and adjacent areas.