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A plodding storm that dumped heavy snow on the Mid-Atlantic region made roads slippery in the Northeast for Monday's commute while travel disruptions continued to ripple across the country days after the same system first began wreaking havoc.

The storm that coated parts of Texas in ice struck with unexpected force on the East Coast, blanketing some spots in a foot of snow, bringing highways to a halt and causing scattered school closures or delays. The federal government was allowing workers to arrive up to two hours later than normal or take unscheduled leave as freezing rain continued.

Travel problems could linger into the afternoon on Monday, with freezing rain and icy conditions as the wintry weather stretched from Missouri to Maine.

The storm canceled more than 3,200 flights Sunday and delayed thousands more, according to estimates from the website Flightaware.com. More than 1,300 flights Monday were already canceled by 8:00 a.m., the greatest share from Dallas/Fort Worth International Airport, which was still reeling from the effects of the ice storm that hit north Texas. About 650 people were stranded at the airport there Sunday night, down from Saturday night when about 2,000 travelers were stranded, spokesman David Magana said.

The forecast for Monday remained uncertain for the Northeast, depending on how quickly the system moves and temperatures rise, according to the National Weather Service. Meanwhile, a winter storm warning was issued for Washington, D.C., and Baltimore, where up to a quarter inch of ice was expected because of freezing rain that could cause power outages.

The expectation was for yet another weather system to follow the same path as Sunday's storm overnight Monday. It was forecast to dump icy drizzle and freezing rain from the New York City area to Boston, National Weather Service meteorologist Greg Heavener said.

Slippery conditions were reported overnight in the New York City area: One crash involving about 20 vehicles closed southbound lanes of Interstate 95 in Greenwich, Conn., for a couple of hours. No serious injuries were immediately reported.

Forecasters said air travel would likely remain a hassle, too.

"I think the further north you look, departures and arrivals could be affected because of icy issues," Heavener said.

What was forecast in the Philadelphia area to be a tame storm system with about an inch of snow gradually changing over to rain mushroomed into a full-blown snowstorm. Bands of heavy snow made for a wide range of accumulation: a foot was reported in Newark, Del. Philadelphia International Airport received 8.6 inches, more than it had all of last year. Other areas received far less: a little over an inch was reported in Pennsylvania's Lehigh Valley, which usually is hit harder than downtown Philadelphia.

Sunday's snow fell so heavily in Philadelphia that yard markers at Lincoln Financial Field — where the Eagles played the Detroit Lions — were completely obscured. It was almost as bad in Pittsburgh for the Steelers, where the snow intensified after the opening kickoff.

Philadelphia fan Dave Hamilton, of Ivyland, layered up for the game in Eagles gear.

"Twenty-seven years I've been a season-ticket holder, I've never seen snow at the game like this," he said. "It just kept coming down."

Heavy snow in the Philadelphia area led to a number of accidents, including a fatal crash on the Pennsylvania Turnpike that spawned fender-benders involving 50 cars, stranding some motorists for up to seven hours. More than two dozen vehicles were involved in another series of crashes on nearby Interstate 78.

Paul Jones, 24, a youth hockey coach from Warminster in the Philadelphia suburbs, was on his way to a game in Lancaster when he got stuck — along with his fiancee, another coach and three players — in a major backup on the turnpike.

The roadway was "snow-covered, slick," Jones said by phone from the car, where he was a passenger and had been at a standstill for more than an hour.

"People are in and out" of their vehicles, he said. "Kids are having a snowball fight on the side of the road, making snow angels, people are walking their dogs."

Stacey Jackson, a spokeswoman for the Philadelphia airport, said Sunday a number of passengers were expected to remain in the airport overnight since area hotels had been full for several days. She said staff would hand out pillows and blankets to travelers to make them "feel at home even though they are not."

Air passengers in the Washington-area experienced increasing delays at both Dulles International and Ronald Reagan Washington National airports.

Virginia, parts of West Virginia and the metropolitan Washington, D.C., area braced for blackouts under steady freezing rain, wet snow and sleet. Parts of northwest and southwest Virginia and southern West Virginia got snow, while sleet and freezing rain prevailed west and north of Richmond.

In Maryland, a chain-reaction accident on Interstate 81 in Washington County involving more than 20 vehicles delayed snow removal efforts for hours. The highway was closed for more than three hours after a tractor-trailer ran into the median to avoid cars that had spun out. It was hit by another tractor-trailer that overturned and spilled its load. Several other tractor-trailers ran off the road and jackknifed as their drivers tried to avoid the crash.

"The small streets, a lot of them are icy," said Mahdi Abdi, 52, a cab driver in Washington. "I don't even go in."

But the nasty weather wasn't limited to the East Coast. Nebraska and Iowa saw snow; multiple weather-related crashes were reported in Wisconsin, including two that were fatal; thousands of customers lost power in Mississippi because of sleet and freezing rain.

A snowstorm that hit along the Utah-Arizona border left hundreds of travelers stranded on Interstate 15 overnight into Sunday. The Arizona Highway Patrol said passengers in about 300 vehicles became stranded after up to 10 inches of snow and slick road conditions prompted the closure of part of the highway. There were no immediate reports of serious injuries.

The specter of bad driving conditions for Monday's commute had some motorists concerned not just about getting to work but getting out at all. New Jersey's new U.S. senator, Cory Booker, tweeted a promise to one Mount Holly resident to help him shovel out his car if he still needed the help in the morning.

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