A Winter Storm Watch has been issued for much of the Chicago area beginning Friday afternoon through Saturday morning ahead of potentially heavy snow over the weekend.
The watch was issued for Winnebago, Boone, McHenry, Lake, Ogle, Lee, DeKalb, DuPage, Kane, Cook, LaSalle, Kendall, Grundy, Will, and Kankakee counties in Illinois. The watch is also in effect for Lake, Porter, La Porte, Newton, and Jasper counties in Indiana.
"A Winter Storm Watch means there is potential for significant snow, sleet or ice accumulations that may impact travel," the National Weather Service said in a statement connected with the storm watch.
NBC 5 Storm Team meteorologists are tracking the developing winter storm system heading into the weekend that could bring several inches of snow across the area.
As the system continues to develop, moving in from the West Coast, details on how much snow it could bring are beginning to narrow.
Friday looks to start off overcast and seasonably cold with highs in the low- to mid-30s before light snow develops late in the evening or during the overnight hours Saturday.
The National Weather Service warms that "travel could be very difficult," especially for the Friday evening commute.
A widespread snow system is forecast to continue throughout the day Saturday, dumping potentially several inches of snow before coming to an end for some locations.
The steady snow should taper off during the afternoon hours Saturday for much of the metro area and in the evening for northwest Indiana.
The real factor that continues to hover over snow total projections is an expected band of lake effect snow.
Lake effect showers keep the snow going overnight for counties closer to the lake, which would have a major impact on snow totals. If the lake effect system develops on the Chicago side of Lake Michigan and shifts east into northwest Indiana, it could bring several inches of additional accumulation to those areas before coming to an end Sunday afternoon and evening.
As of Thursday, models showed numerous possibilities for snow totals this weekend.
At O'Hare Airport, the Global Model predicted around 4 inches of snow, the Euro Model showed up to 3 inches and the Nam Model went as high as 8 inches.
At the same time, the snowy system will usher in a bitter blast that could bring the coldest air of the season so far.
Highs Saturday look to sit in the upper-20s before plunging Sunday to the mid- to upper-teens with wind chill readings near zero – where they will likely stay to start off the work week.
We will continue to update our forecasts as the system develops. Check back for the latest information.