A wet and windy Wednesday will continue through the nighttime hours.
Freezing rain is mostly likely to create accumulating ice in counties along the Illinois and Wisconsin state line where temperatures are at the freezing mark or even a little below.
McHenry County remains under an Ice Storm Warning through 6 a.m. Thursday.
Portions of Cook, Dupage, Kane, Lake counties in Illinois are under a Winter Weather Advisory until 6 a.m. Thursday.
Freezing rain is to continue into Wednesday and even into Thursday morning north of I-88 and especially along and either side of the Wisconsin line. It is expect to become light and more occasional, even ending at times, except for lingering drizzle or sprinkles. Our expectation is most ice accumulations will fall in the range 0.25 to 0.50″ though some spots could end up with an much as an inch of ice.
Studies of icing indicates with a 0.25 to 0.50″, some branches break and this can in turn take down some power lines.
The added weight of that ice plus additional stress brought to bear by strong “ENE” winds suggests there may be some damage and some power issues in hardest hit areas—which include Lake, McHenry, Boone, Winnebago, portions of northern Cook as well as DuPage, Kane and DeKalb counties.
Road de-icing chemicals work well at current temps so major thoroughfares which have been treated are likely to be just wet. But extreme care should be exercised on driveways, sidewalks and less traveled and untreated roadways, bridges and off ramps which could be icy and create problems.
Southeast of the city heavy rain and even a few embedded thunderstorms with the rain are possible.
By the time this storm’s rains end, much of the Chicago area is likely to receive anywhere from 0.8″ to 1.6″ of rain—making this the heaviest rain to occur here in more than 2 months (since December).