Area braces for another slap by Old Man Winter

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Updated: March 22, 2012 10:36PM

A “potent” winter storm could bring up to 7 inches of wet, heavy snow to the Chicago area starting late Thursday evening.

The National Weather Service has issued a winter weather advisory for the Chicago area from southern Wisconsin into Northwest Indiana, with a potent winter storm expected moving across the southern Great Lakes region on Thursday evening, bringing rain that will quickly turn into wet snow which “may become heavy at times.”

Snow could fall as fast as an inch per hour after 8 p.m., according to the National Weather Service advisory, which is calling for between 4 and 7 inches of snow across the area. The highest snow totals are expected in DeKalb, Kane, DuPage and northern Cook counties, with only a few inches of accumulation south of I-80 and into northwest Indiana.

A winter storm watch issued earlier has been canceled and changed to the winter weather advisory, which begins at 6 p.m. Thursday and lasts through 9 a.m. Friday for Cook, McHenry, Lake, Kane, DuPage, Kendall, Will and Grundy counties in Illinois, and Lake, Porter and LaPorte counties in northwest Indiana.

Snow is expected to begin falling Thursday evening, moving from the Rockford area to the southeast, with the heaviest snow late in the evening and early Thursday night, gradually tapering off early Friday morning, according to the weather service. The snow could also be accompanied by thunder at times, with the heaviest snowfall during those periods.

It will make for poor driving conditions Thursday night as wind-whipped slushy snow could accumulate quickly and leave roads slick, the NWS said. Strong winds may blow the wet snow up onto cars, reducing visibility for drivers.

The Illinois Tollway is preparing to mobilize its full fleet of 183 snowplows in response to the snowfall and the Tollway’s Snow Operations Center is open, to manage the agency’s systemwide response.

“It is possible that this storm could impact drivers this evening as well as tomorrow’s morning rush hour, so we ask our customers to drive safely and allow enough time to arrive at their destinations,” Illinois Tollway Executive Director Kristi Lafleur said.

To respond to this weather event, the Illinois Tollway will have a full complement of more than 200 staff and supervisors per shift to ensure that roadways are kept clear of snow and ice. To help with snow removal efforts, the Tollway has cancelled all temporary lane closures from 5 p.m. Thursday to noon on Friday.

Light snow could continue through Friday morning before ending midday, with additional minor accumulations, especially across northwest Indiana.

People with health concerns should especially use caution when shoveling because the high moisture content of the snow could make it heavier and more difficult to move, the weather service said.

Temperatures are expected to hit a high near 37 Thursday with a low around 31, and will climb back up to around 36 Friday, with cloudy skies sticking around through Friday, according to the NWS. Saturday will be mostly sunny with a high near 34.