A Winter Weather Advisory is in effect for most of the Chicago area today into this evening with an Ice Storm Warning for southernmost counties (LaSalle, Grundy, Kankakee, Iroquois, Ford and Livingston) into central Illinois. Temperatures in the 20s eventually reaching only the lower 30s, freezing rain and sleet mixed with a little snow will cause icing and glazed-over conditions and very dangerous travel and outdoor activities. Ice accumulation and easterly winds gusting to 30 mph will weight-down trees and possibly lead to downed power lines. Rain/freezing rain will changeover to snow with 1 to 3-inches accumulation possible by this evening before snow ends from the west later tonight.
Heaviest icing of a quarter-inch or more is expected in southernmost counties under the Ice Storm Warning. Counties along the Illinois-Wisconsin state line will sit on the northern fringe of the precipitation with a little light icing mixed with mainly 2 to 4-inches snow accumulation. Note the progress of the precipitation on the Regional Weather Radar Mosaic map.
The map below shows the huge expanse of the country impacted by this storm system – with Winter Storm Warnings and Advisories all the way from Texas, Oklahoma, Kansas, and Missouri through Illinois, Indiana and Ohio today spreading into Pennsylvania, New York and New England by Saturday.
