New Years Weekend winter Storm Update #5

(10:30AM - 1/1/22) A winter storm will move through the region today, impacting the state and region. This winter storm will produce a swath of accumulating snow across the northern half of the state, with mixed precipitation across Central Illinois.

Summary...
A storm system will move from the Plains this morning, through the Mid-Mississippi Valley and Ohio Valley this afternoon into tonight, and then into the Northeast by Sunday morning. This storm system will bring a swath of accumulating snow across the northern half of the state, this morning through late tonight and early Sunday morning. A transition zone with mixed precipitation will set up across Central Illinois. Additionally, lake enhancement/lake effect snow will be likely across Northeast Illinois during this time as well.

With this update with have increased snowfall amounts across portions of Western Illinois, as well as near Lake Michigan in portions of Northeast Illinois. Additionally, we had adjusted gradients on either side of the main snowfall axis based on real time observations and latest model data. It should be noted that even though the storm system has begun, model guidance is still in a bit of disagreement regarding a few things. We will continue to watch real time observations, and will provide further updates if needed.

​Forecast...
Precipitation has spread northeastward across Northern and Central Illinois this morning. Across the northern half of the state, precipitation will be all snow for the duration of this winter storm. Snow is expected across the northern half of the state from the onset this morning, through this afternoon and evening, before ending with time tonight or early Sunday morning. Snow will be moderate to heavy at times, with snowfall rates up to or in excess of 1" per hour at times, especially late this morning through this evening. Lake enhanced/lake effect snow is also expected across Northeast Illinois, which will add to snowfall totals for that area. Additionally, wind gusts of 20-40MPH can be expected as well, which could cause some blowing and drifting of snow.

Further south across Central Illinois, while portions of the area may stay as all snow for the duration of the winter storm, a transition zone will set up up across Central Illinois. Along this transition zone; a mix of snow, sleet, freezing rain and rain will be possible. Minor accumulations of sleet and ice will be possible, in addition to some snowfall accumulation. Even further south across the southern half of the state, precipitation will come in the form of rain and t'storms...However, at this time no severe weather threat is expected.

Snowfall totals upwards of 2-5" to 4-7" are expected across much of the northern half of the state, with snowfall total of 6-9" expected across far Western Illinois. Across Central Illinois, where the wintry precipitation transition zone will set-up, snowfall totals may vary greatly over short distances and will be nonuniform...As well as there being the likelihood for minor freezing rain and sleet accumulation.

​Below is the snowfall forecast for this winter storm.

JP