The storm was part of a system that started in in Montana, hit the Dakotas and Minnesota on Monday and then barreled through Wisconsin and Illinois on its way to Washington, D.C., where it was expected late Tuesday night. As the storm pushed toward the Mid-Atlantic region, people there were gathering supplies and airlines were canceling flights.

Since the 2011 blizzard that dumped 20 inches on Chicago, the nation's third-largest city has had it pretty easy snow-wise. But the storm that was moving through Tuesday could end up dumping the most there since that blizzard, after a relatively mild winter last year and a slow start to this year's.

Some in Chicago were caught off guard by the last gasp from Old Man Winter.

"I thought it was just media hype," said Stacia Kopplin, who was fleeing her financial services job shortly after noon and walking through the blast of wet snow to catch a train home to the suburbs.

Schools were closed in Minnesota, Wisconsin and Illinois, where officials urged caution on snow-slickened roads. In western Wisconsin, a semi-trailer slid off a snow-covered interstate near Menomonie and into the Red Cedar River, killing one person. Authorities said they were searching for a second person, believed to be a passenger.

Airlines canceled more than 1,100 flights at Chicago airports, prompting delays and closures at others around the region. Airlines along the storm's projected path were already cutting flights too, including about 450 on Wednesday, most of them at Dulles and Reagan National airports in the Washington area, according to FlightAware.com. Daniel Baker, CEO of the flight-tracking service, said he expected the numbers to rise.

In Chicago, officials were working to keep Lake Shore Drive safe. The February 2011 blizzard embarrassed the city when hundreds of cars and buses were entombed in snow on the roadway that runs along Lake Michigan and people were trapped overnight.

City government has taken steps to prevent a repeat. Officials have opened a removable barrier in the median of the four-lane roadway to allow emergency vehicles quicker access to trouble spots. Plows and salt-spreading trucks are also in easier striking distance of Lake Shore Drive, and they started treating the roadway hours before snow began falling.

"We are prepared as a city to deal with this snow," said Mayor Rahm Emanuel at Chicago's emergency snow command center, where officials keep an eye on a bank of TV monitors feeding in real-time images from 1,500 cameras and data from roadway sensors.

Elsewhere along the storm's path, many were taking things in stride.

"It's not that bad at all," said 47-year-old Alicia Aldrete, who was out walking her dog in Madison, Wis. "Just make sure you shovel immediately, put lots of salt on the ground and also store lots of food in case of emergency."

Dave Koch, manager at Paul's Tavern in Dubuque, Iowa, said business was surprisingly busy this afternoon as people came in to escape the snow. At least 5 inches of snow had fallen.

"In general, everyone's attitude is pretty tired," Koch said. "I think people are tired of the snow and the gloomy weather."

In St. Paul, Minn., where 7 inches of snow had fallen, 55-year-old Mario Showers was shoveling sidewalks around a downtown church.

"With Minnesota, ain't no telling when the snow's gonna come, you know," said Showers. "The way I think about it is that, you've got four seasons, and every season brings about a change, you know. So, you've got to take the bitter with the sweet, that's all. So this is the bitter right now."

But in Virginia, the forecast was already causing a run at some supermarkets At the Food Lion in Staunton, shelves that were stocked ahead of the storm were being cleared by customers.

"Bread, milk, eggs and beer, all the necessities," manager Everett Castle said.

People in Washington, D.C., were bracing for 3 to 7 inches. The mountains of western Maryland could get up to 16 inches by Wednesday night. Minor tidal flooding was possible along the Delaware coast, the western shore of the Chesapeake Bay and the lower Potomac River, the National Weather Service said.

As miserable as things could get for commuters, taxi driver Balwinder Singh of Herndon, Va., said he was looking forward to the storm.

"People tip better in the snow," he said.

As the heaviest snow fell in Chicago, residents were working their shovels and snow-blowers.

Pat Reidy said she skipped work and did 40 minutes of yoga as a warm-up for the heavy lifting she was doing in her neighborhood near Wrigley Field.

"I'm trying to avoid a heart attack," the 52-year-old finance worker said.

Mike Morawski, 53, was helping clear the sidewalk in front an older neighbor's home.

"We don't want her digging out," he said. "She's a tender, little woman, a piano teacher. She doesn't need to be shoveling."

Chicago's love-thy-neighbor ethos has its limits, though. With the winter blast, Morawski expected the return of an old city tradition in which residents clear a parking space and keep it reserved with a lawn chair.

"They'll all come out tonight, believe me, when people start digging out," he said.