Wed-Fri, Feb 23-25th Winter Storm Update #5

(10:45AM - 2/24/22) A winter storm will continue to impact the region and state, through early Friday morning. This winter storm will produce a swath of accumulating snow/sleet/ice across the region and state during this time.

Summary...
Real time observations and model guidance continues to support the going forecast. The main changes with this update were to bring the potential for some freezing rain/ice accumulation a bit further north into Central Illinois, as well as increase snowfall accumulation to 2-5" across Northeast Illinois due to increased confidence in lake effect snow contribution

​An initial lead wave moved through the Ohio Valley Wednesday through Wednesday night, bringing with it an initial round of wintry precipitation across the southern half of the state. Furthermore, a main storm system is developing across the Southern Mississippi Valley this morning, and is expected to track near the Ohio Valley this afternoon and tonight, and eventually into the Mid-Atlantic by Friday morning. This storm system will bring a renewed push of wintry precipitation across the region and state, this morning through Friday morning.

Wintry (Snow/Sleet/Ice) Aspect Forecast...
Wednesday Afternoon - Thursday Morning, Feb 23-24th ~ Lead Wave Event:
An initial lead wave moved through the Ohio Valley Wednesday through Wednesday night, with an associated area of precipitation traveling along with it. Precipitation in the form of a mix of freezing rain/sleet/snow pushed across Southern Illinois, Wednesday afternoon through Thursday morning. This period of mixed precipitation brought light accumulations of snow/sleet/freezing rain across Southern Illinois during this time.

This Morning - Friday Morning, Feb 24-25th ~ Main Winter Storm Event:
​As the main storm system moves through the region, an associated renewed push of precipitation will move across the state and region, this morning through Friday morning. This renewed push of precipitation, in the form of snow/sleet/ice, is moving into portions of Western and Southwestern Illinois mid to late this morning. This area of precipitation will further develop and spread across much of the state from midday today through tonight, before ending by late tonight or early Friday morning. A transition zone will set up much of this period across Central and Southern Illinois. Across this zone, precipitation types from south to north will range from rain across far Southern Illinois to freezing rain to sleet and then to snow across Central Illinois. North of this transition zone across affected areas of Northern and other portions of Central Illinois, all of the precipitation will fall as snow. Snow will vary in intensity, but will generally be light to moderate at times, with snowfall rates of 0.5"+ an hour possible at times.

​In additional to the synoptic aspect to this winter storm period, conditions will be favorable for lake enhanced and lake effect snow across portions of Northeast Illinois, through Friday morning. This will likely enhance snowfall totals for portions of the Chicago area near Lake Michigan.

​Below are the snowfall and ice forecasts for this winter storm.

​​​​​​​Impacts...
-An axis of of snow/sleet accumulation of 1-3" across Northern and Central Illinois, with 2-5" of snowfall accumulation in Northeast Illinois near Lake Michigan. Sleet accumulation of a dusting to 1" across Southern Illinois.
-Ice accumulations of a glaze (Up to 0.10") to 0.10-0.25" across Southern Illinois.
​-Tree damage and power outages possible across far Southern Illinois, due to ice accumulation.
-Widespread travel impacts likely across much of the state.

JP