11:30pm Update: Heaviest of the snow now moving to the east with lighter snowfall back to the west where visibility is also beginning to improve a little. Take it slow tonight and Friday morning.
9:30pm Update: Radar shows the heavier snowfall now moving to the northeast, but pockets of moderate snow moving in from the west. These snow showers will continue, beginning to taper off between 12am-2am. There will still be a few flurries through sunrise, but accumulating snow will be done.
Roads have become quite hazardous with the heavy snow sticking. Temperatures in the low 30s will keep the threat for slick and icy conditions through Friday morning.
6:00pm Update: Bands of heavy snow continue to move across northern Illinois and southern Wisconsin Thursday evening. Snowfall rates of an inch per hour at times have been occurring, producing snow totals already between 1-3 inches.
Heavier snow is beginning to move back in, dropping visibility down to half a mile or less in many locations. The majority of the snow so far has been confined to grassy and colder surfaces. But as the heavier snow fills back in, accumulations will begin on the roads that have just been wet so far. Road conditions have deteriorated over the last couple of hours as the heavier snow has moved back in.
The heavy and wet snow will make road conditions slick through the evening. This combined with the reduction in visibility will cause difficult travel, especially once the sun sets. The heavier snow will last through 10pm, before it begins to taper off around Midnight. There will still be a few flurries/light snow showers through Friday morning, but the majority of the accumulating snow will have ended.
Snowfall totals of 4-6 inches still look to remain on track, with most coming in close to 4-5 inches.