The beginning of our next late season snow event is starting to unfold Wednesday evening. A few light snow showers have been working through parts of northern Illinois and southern Wisconsin. While most of this is likely not reaching the ground, I have received some reports that there are a few light snow showers falling. Anything that does comes down is not expected to accumulate. Skies will remain mostly cloudy through the night with temperatures falling to the low 30s.
WINTER STORM WARNINGS have been issued for Stephenson, Jo Daviess and Carroll counties. WINTER WEATHER ADVISORIES have been issued for Winnebago, Boone, McHenry, Ogle, Lee, DeKalb, Whiteside, Green, Rock and Walworth counties. These go into effect Thursday afternoon.
Temperatures during the day Thursday will warm to the upper 30s and low 40s. As moisture increases through the morning, a light mix of rain and snow (just rain for some) will develop after Noon. Precipitation will continue to spread across the region, but as it does temperatures will actually begin to fall into the middle 30s by late afternoon. This will allow any mixed precipitation to switch over to all snow. The snow will be light initially but should pick up in intensity through the evening, turning heavy late evening.
Temperatures leading into Thursday have been unseasonably warm. And this warmth may, initially, limit impacts on the roads when the snow begins. But as heavier snowfall rates develop the warmth of the surface may be overcome, allowing the snow to quickly accumulate on the roads. This could cause some issues for the evening commute, most likely after sunset. The heaviest of the snow is expected to fall late evening, into the overnight, before tapering off into Friday morning. Lingering impacts on the roads are possible Friday morning.
Snowfall totals look to range between 4-6 inches north of I-88, with the highest falling close to the state line. To the south, 2-4 inches is possible. The snow is expected to be very heavy and wet. Snow to liquid ratios will range from 8:1 to 10:1. A rain/snow mix is then possible during the afternoon Friday, before clearing out Friday night.