A deadly pre-winter blizzard that left nearly 2.4 million Midwest customers without power Friday swept quickly across the Great Lakes region, leaving up to two feet of snow and a massive cleanup operation to reopen major airports and clear highways clogged with abandoned vehicles.

In addition, severe thunderstorms associated with this major cold front dropped at least one tornado in northeastern Pennsylvania on Friday evening, reportedly causing damage and some minor injuries in Luzerne County. No serious injuries or fatalities have been reported, although many areas have been isolated due to downed power lines, tree limbs and flooding.

The storm, which has been blamed for at least three deaths, continued its eastward march, though forecasters expect the heavily populated Washington, D.C.-to-Boston corridor to be spared any significant snowfalls. Gusty winds, some topping 50 mph, driving rain and even the possibility of tornadoes are predicted for the East Coast through New England.

A Fed Ex cargo plane arriving Friday morning at Chicago's O'Hare International Airport slipped into the mud off the only open runway, and crews were working to tow it away. There were no injuries, said Wendy Abrams, a spokeswoman for the Chicago Department of Aviation.

A 50-mile stretch of Interstate 70 in mid-Missouri was shut down, while about 2.4 million customers across central and southern Illinois and parts of Missouri were without power early Friday. The St. Louis Arch was even closed to visitors.

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The local FOX News affiliate in St. Louis, Mo., reported that 450,000 people were without power in the metropolitan area there, and that number is expected to grow, as gusty winds, snow and ice down more trees and power lines.

The wintry system struck Thursday from Texas to Michigan.

In the Chicago area, the National Weather Service issued a winter storm warning until noon, predicting six to 12 inches of snow. Winds gusted to over 30 mph as the storm arrived in full by the morning rush hour. The service advised people in central Illinois to avoid traveling, if possible. More than 75 percent of all roads in Illinois are now covered by at least some snow.

"It looks like it's going to get messy," said Tim Halbach, a meteorologist in the Chicago suburb of Romeoville. "There could be times where some areas see 2 inches of snow per hour."

At Chicago's O'Hare International Airport, more than 400 flights scheduled for Friday were canceled Thursday, allowing customers more time to change their travel plans. Hundreds of incoming flights have also been canceled; the airport is down to one runway.

Laura and Ron Whittingham said early Friday that their United flight to Las Vegas was leaving on time from O'Hare, one of numerous airports where most flights were canceled.

"I guess we're just the lucky ones," Ron Whittingham said. "We are going to Vegas, so that's a good thing, right? We're starting off lucky."

By 3 p.m. EST, Chicago O'Hare Airport reported it was returning to limited service, along with airports in St. Louis and Kansas City.

Chicago has enjoyed temperatures in the upper 60s for the past few days, but light coats have been replaced with parkas, and people got out their snow shovels to dig themselves out of the snow. Meanwhile, 270 salt spreaders stood ready to hit the roads.

There was thunder and lightning around Chicago earlier Friday morning, and at least one foot of snow is expected in the Windy City later in the day.

Sleet, snow and freezing rain forced the cancellation of 200 flights out of Dallas-Fort Worth International Airport and closed some schools. Most Thursday night flights out of Lambert-St. Louis International Airport were canceled.

Crews at Kansas City International Airport put down 110 tons of sand, 30,000 gallons of liquid de-icer and 4 metric tons of granular de-icer by Thursday night. Two-dozen Kansas counties were in a state of emergency.

High winds hit the Dayton, Ohio, suburb of Vandalia shortly before dawn Friday, knocking down power lines and tearing siding and shingles off homes. Police Chief Doug Knight described the damage as minor and said there were no injuries.

Snowfall in parts of Oklahoma ranged from 2 inches to nearly a foot, while parts of Illinois prepared for 6 to 12 inches. Varying amounts were forecast for Missouri, Kansas and Arkansas.

The weather even forced the postponement of the state high school football playoffs in Oklahoma for the first time in 14 years. Snowfall there ranged from 2 inches to nearly a foot, while parts of Illinois prepared for 6 to 12 inches. In southeastern Wisconsin, forecasters warned that winds and rain could bring near-blizzard conditions.

An Oklahoma man was killed Thursday when his vehicle skidded on an icy road and hit an oncoming tractor-trailer. Also Thursday, on Interstate 44 near Rolla, Mo., a motorist involved in an earlier accident was standing near his vehicle when a semitrailer jackknifed and slid into the car, killing him.

"It's just too darn slick. It's going to be a mess out there for a day or two," said Taylor Hunt of the Missouri State Highway Patrol.

A driver died in Boone County, Mo., on Thursday when his car was struck by a snow plow blade, said Highway Patrol spokesman Lt. John Hotz. Two passengers were taken to a hospital with serious injuries.

The state trooper who responded to the crash then apparently became stranded himself.

"Apparently there were several of our troopers that were stranded out there all night," Hotz said. "We're having trouble even getting patrol cars around."

In Oklahoma, two accidents on Interstate 40 snarled traffic for most of Thursday. A 16-vehicle pileup involving an ambulance and eight semitrailers forced the closure of the highway in central Oklahoma for nearly 13 hours, while a tractor-trailer carrying some radiological material overturned in Oklahoma City.

No hazardous material leaked, said Highway Patrol trooper Kera Philippi, although the highway was shut down for more than six hours.

At the Nevada Fuel Mart in southwest Missouri, Rose Dozier said most truck drivers heading south stopped early Thursday night. They reported near-zero visibility before the snow began to subside.

"The drivers are all professionals and they're used to it," Dozier said. "They said a lot of cars are not."

In the Texas Panhandle, roads were covered with ice and up to 7 inches of snow.

Clay Ender, who works for a heating service company, struggled to get around in the 3 inches of snow that fell overnight in Lubbock. A trip across the city that usually takes 20 minutes stretched to an hour, he said.

"There were so many cars spinning out of control. They couldn't get any traction," he said.

Jennifer Stark with the National Weather Service in Topeka, Kan., said the storm seemed especially impressive because it had been preceded by unseasonably mild weather. Temperatures approached, and in some places eclipsed, record highs earlier in the week.

The system roared through the Northwest and Rockies earlier in the week. Coming on the heels of near-record high temperatures, it rolled through Kansas on Wednesday, coating tree limbs and power lines with half an inch of ice. By Friday, the storm was moving northeast through Illinois on the way to Canada.

The eastern Missouri towns of Leadington and Park Hills put off plans for two holiday tree lightings and a joint Christmas parade, said Tammi Burns, executive director of their shared Chamber of Commerce. She said the communities will celebrate next Thursday.

"Keep your spirits up," she said. "Be thankful it's getting cold for Christmas."

The Associated Press contributed to this report.