A freezing rain advisory had barely expired when the National Weather issued a winter storm advisory with up to 4 inches of snow expected to fall this afternoon and tonight.
Rain is expected to change over to snow by the middle of the afternoon "in time for the evening rush," the weather service said in the advisory.
"The threat for a period of heavy snow could result in reduced visibilities under a mile at times and rapid accumulation on area roads during the evening commute," the weather service warned.
The most snow is expected to fall north of I-88 and the North Side of Chicago, it said.
The morning commute was slickened by sleet and freezing rain across northeast Illinois, mainly along I-88 and north of the expressway, according to the weather service.
Photos: Chicago winter 2012-13
Meanwhile, New England braced for a possibly record-setting winter storm, with forecasts of up to two feet of snow prompting local officials to urge residents to prepare.
Forecasters warned the snow would begin lightly on Friday morning but ramp up to blizzard conditions by afternoon, leading Boston Mayor Thomas Menino to order the city's schools closed Friday. He asked businesses to consider allowing staff to stay home.
"We are hardy New Englanders, let me tell you, and used to these types of storms. But I also want to remind everyone to use common sense and stay off the streets of our city. Basically, stay home," Menino told reporters. "Stay put after noontime tomorrow."
The National Weather Service said Boston could get one to two feet of snow on Friday and Saturday, which would be its first major snow fall in about two years. Light snow is expected to begin falling around 7 a.m. EST on Friday, with heavier snow and winds gusting as high as 60 to 75 miles per hour as the day progresses.
"It's the afternoon rush-hour time frame into the evening and overnight when the height of the storm will be," said Kim Buttrick, a meteorologist at the National Weather Service in Taunton, Massachusetts. "That's when we expect the storm to begin in earnest."
The heaviest snow was expected around Boston, the region's most populous city, with cities from Hartford, Connecticut to Portland, Maine, expected to see at least a foot.
If more than 18.2 inches of snow fall in Boston, the storm will rank among the 10 biggest snowfalls on record in the city. The heaviest snowfall ever recorded in Boston was a 27.6 inch dump that accompanied the blizzard of February 17-18, 2003.
The storm's timing brought back memories of the blizzard of 1978, Boston's second-heaviest recorded snow fall, which roared in on an afternoon, dropping 27.1 inches of snow, trapping commuters on roadways and leaving dozens dead across the region, largely as a result of downed electrical lines.
Peter Judge, a spokesman for the Massachusetts Emergency Management Agency, said one of the state's biggest worry is power outages.
"It being winter, folks losing their power means they're also losing their heat, and if you lose heat during the middle of the storm, you're not going to be able to go out to get to a shelter," he said, adding that the agency would begin 24-hour operations at its emergency compound at noon (1700 GMT) on Friday and would be in close contact with local utilities.
Unlike the 1978 blizzard, which had been forecast to drop far less snow than it actually did, he said he hoped several days of news coverage about this storm would prompt people to stay off the roads.
"People have been warned, they have been told what the issues are," Judge said. "We don't expect people to be surprised."
Reuters contributed to this report.
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