Serious and widespread icing has developed as expected with as much as 1/2″ of ice reported coating surface just north of the Wisconsin line in Pell Lake Wisconsin and widespread ice coverage approaching 2/10s of an inch in many areas north of I-88. Temps have hovered near or just below freezing and heavy rain has fallen into the cold air producing the icing.

According to ComEd’s outage map, over 113,000 customers in the Chicagoland area are without power as of 10:22 p.m. CST Wednesday evening.

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.

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).

The storm responsible is producing major snowfall north from central and northern Wisconsin west into the Dakotas. Snowfall may ebb for a time in places like the Twin Cities where as much as 7″ is already down—but will pick up again later tonight and into Thursday amid powerful winds. When snow is done—as much as 16 to 24″ may have fallen in harder hit locations.

Coming days will see a shot of cold air hold daytime temps to the 20s Friday warming over the weekend to the 30s Saturday and the 40s Sunday.

The pattern remains VERY ACTIVE—with additional late winter storms in the pipeline over the next two weeks. Precip is to continue above normal.

The next storm hits with rain in Chicago—and potentially heavy rain, strong winds and a boost in temps into the 50s likely Monday.  But modeling continues to take that system out of the area by next Tuesday–Election Day here. 

Still another set of systems is due the middle and end of next week—with somewhat colder air in place. This places these system’s rain/snow line closer to Chicago.  Yet another storm early the following week looks, from this distance to be a windy rain producer.

Temps this week will finish a bit above normal—compared to last week which came in 8-deg above normal. And the week which follows next may produce a modest 1-deg temp surplus based on very preliminary modeling.

ICE STORM WARNING McHenry, Boone and Winnebago counties through 6am CST Thursday.

WINTER WEATHER ADVISORY for Lake county, IL as well as northern Cook, Kane, DeKalb and Ogle counties also until 6am CST Thursday…..

TONIGHT: Rain, with downpours at times this evening—even a possible t-storm Chicago and south—becoming lighter and more occasional with mixed drizzle later tonight.  FREEZING RAIN with additional ice accumulations, essentially north of I-88, also becoming lighter and more occasional after this evening. Total ice accumulations from ¼ to 1.2″–locally higher near the Wisconsin light.  Temps hold nearly steady in the low and mid 30s.

THURSDAY: Clouds linger, turning windy and colder. A bit of drizzle or a patch of light rain or—in northern counties—perhaps a bit of light freezing rain—in the morning. Wind gusts build to 40 mph in the afternoon. High 37 but falling to the low 30s by nightfall.

THURSDAY NIGHT: Clouds break, windy and colder. Low 20.

FRIDAY: Mixed sun then cloudy, colder. Chance of mainly nighttime flurries. Much lighter winds. High 27.

SATURDAY & SUNDAY: A good deal of daytime sunshine—but clouding over again later Sunday. Temps warm over the weekend. High Saturday 38. Sunday’s high 44—but chillier each day along Lake Michigan.

MONDAY: Rainy, windy and mild. A few possible t-storms. High 53.

TUESDAY (Election Day): Clouds break allowing some sunshine—but precipitation-free and colder. High 41.

WEDNESDAY: Becoming cloudy. Chance of snow and/or rain. High 37.