Winter Storm Watch Issued, Mix Likely Wednesday Afternoon

Winter Storm Watch Issued:

While you were fast asleep, the National Weather Service expanded the Winter Storm Watch eastward to include Green, Rock, and Walworth Counties up in S. Wisconsin. 

This watch will begin Wednesday afternoon, lasting into Thursday afternoon. Only time will tell if Chicago or Quad Cities will put a watch out for extreme N. Illinois Counties. 

Fairly Tranquil Tuesday:

Ahead of the mess that lies ahead for midweek, the tranquil conditions we saw Monday carries on into our Tuesday. The difference-maker however would be the frontal passage that occurred last night. 

That will result in not only a cooler morning, but also a cooler afternoon with highs in the low 30s. We do manage to squeeze in a good amount of sunshine early on before cloud cover gathers up throughout the afternoon.

Midweek Storm System:

Forecast models continue to showcase a swath of snow happening across portions of Minnesota and Wisconsin this evening. While much of the activity aims to remain north of the IL/WI border, a few may track into northern Illinois.As we've been hinting at, the highest impacts will be felt during the latter half of Wednesday. 

This means that you'll more than likely get to your destination Wednesday morning without any issues. As a powerful low pressure system lifts northeastward, rich-moisture will stream out ahead of it, resulting in widespread rain by mid-day. Rain could fall heavy at times and it's not out of the question that we may hear a few rumbles of thunder. It's after mid-day that we'll need to closely monitor our temperatures as a strengthening northeasterly wind will send them closer to the 32° mark.

Once we get cold enough, this will increase the likelihood mixed precipitation. At this point in time, freezing rain, sleet, and snow will all be on the table. Like the last winter storm to impact northern Illinois and southern Wisconsin, road temperatures will be warm enough to counter any ice accumulations that occur at first. Though that definitely can't be said for the evening commute as slick conditions will be more than likely. 

Forecast models from there decrease the intensity of the mixed precipitation going into the Wednesday night time frame, with most if not all of it coming to a close during the early stages of Thursday morning. To clarify, it doesn't take much ice for impacts to be felt. 

Windshields become coated, bridges become slick, and a small amount of ice accumulates on trees when .10" to .25" of ice is observed. Past that, you're looking at bigger problems such as icy roads and isolated power outages. Thursday dries out quickly. However, a strong wind will be present on the backside. Winds out of the west will be able to gust up to 40 mph at times, resulting in what will be another cold end to the work week. Expect highs in the low 20s Friday.