(Adds deaths, power outages, state of emergency in Oklahoma)
By Carey Gillam
Dec 9 (Reuters) - A deadly winter storm that drove parts of the United States into a deep freeze over the weekend kept a tight grip on the nation on Monday, as bitter temperatures, snow and ice spread across the East Coast, snarling traffic and knocking out power to thousands.
As much as 5 inches of snow were forecast for Monday night into Tuesday for an area stretching from Virginia into New York, the National Weather Service (NWS) said.
Meanwhile, dangerously cold temperatures and wind chills were forecast to persist in the western half of the United States, the weather service said, with temperatures about 10 to 30 degrees below average from the Rockies to the Great Lakes and lower Mississippi Valley.
"I don't think things are going to warm up anytime soon," said Bruce Sullivan, National Weather Service meteorologist.
Thousands of homes and businesses were without power Monday morning, and thousands of flights were delayed as snow and ice covered roads, highways and airport runways from Texas and Oklahoma east to Virginia and north through Pennsylvania.
Northern Maryland received 7 to 10 inches of snow over the weekend, while central and eastern Pennsylvania got 4 to 10 inches, and parts of New York received up to 10 inches through Monday morning. Sleet and freezing rain also pummeled the area, according to the National Weather Service (NWS).
The Arctic effect was widespread, stretching from the west coast to the east. The temperature in Jordan, Montana, fell to 42 degrees below zero Fahrenheit (minus 41 degrees Celsius) on Saturday, the lowest U.S. temperature recorded during the storm.
Among other lows, Burns, Oregon, in the northern part of the state, hit a record minus 30 degrees Fahrenheit on Sunday, said Sullivan.
Minneapolis was forecast hitting a high of 1 degree Fahrenheit (minus 17.2 Celsius), with wind chill values as low as minus 21 degrees.
On one stretch of highway near Philadelphia, more than 50 cars and trucks were caught in a series of chain-reaction crashes on the Pennsylvania Turnpike on Sunday afternoon. One man was killed when he left his vehicle after the crashes, officials said.
AAA Mid-Atlantic, the auto group, said it pulled 109 vehicles out of snow and ice in Pennsylvania on Sunday, compared with three the week before.
At least three people were killed in weather-related car accidents in Arkansas and Tennessee as well, authorities said.
Virginia officials warned drivers of hazardous travel conditions, said Laura Southard, a spokeswoman for the state Department of Emergency Management.
The winter storm claimed at least two lives in Oklahoma, including a 5-year-old boy who died after a van he was riding in flipped on an iced-over bridge on Dec. 5, authorities said. A homeless man in Oklahoma City also died, succumbing to the cold beneath an overpass also on Dec. 5, according to police.
The heavy snow and harsh conditions were on display during Sunday's National Football League matchup between the Philadelphia Eagles and Detroit Lions in Philadelphia.
At times it was nearly impossible to see the game from his seat in the upper deck of Lincoln Financial Field, said Eagles season ticket holder Pete Peters.
"For the first half of the game it was a complete whiteout," Peters said. "I was shivering, my teeth were chattering by the fourth quarter."
While he was at the game, Peters' wife and daughter were stranded at the Philadelphia airport when their flight to Orlando was canceled.
COLD PERSISTS IN SOUTH, CENTRAL U.S
Frigid temperatures persisted in the nation's midsection on Monday morning, and travel was snarled in airports and along roadways due to icy conditions.
More than 1,600 flights were canceled nationwide on Monday, according to tracking website Flightaware.com, with "excessive delays" reported at Boston's Logan International Airport, Chicago's O'Hare International, and Philadelphia International airport, among others.
About 650 travelers were stranded overnight in the Dallas/Fort Worth International Airport overnight Sunday, officials said. Still, that was an improvement from the more than 2,000 people who were forced to sleep on cots and chairs Saturday night and 4,000 people stranded in the airport on Friday night.
Dallas/Fort Worth airport had four runways fully operational early Monday, allowing some 500 flights to be scheduled for departure. About 350 flights remained canceled in Monday, airport officials said.
Some 267,000 customers in Texas lost power at the height of the storm, according to utility Oncor. About 21,000 homes and businesses remained without power statewide on Monday, Oncor said.
In southeastern Oklahoma, about 4,000 homes and businesses were without power on Monday, according to Oklahoma Corporation Commission spokesperson Matt Skinner, who said service would likely be restored by Thursday or Friday.
State health officials said 200 people suffered injuries related to the storm.
Oklahoma Governor Mary Fallin declared a state of emergency, citing "prolonged sub-freezing temperatures, dangerous road conditions and power outages." (Reporting by Carey Gillam in Kansas City; Additional reporting by Heide Brandes in Oklahoma City, Jana Pruet in Dallas, Dave Warner in Philadelphia and Ian Simpson in Washington, D.C.; Editing by Jeffrey Benkoe)