Winter storm slams northeastern U.S. with Arctic punch WASHINGTON (Reuters) - A winter storm packing snow and Arctic cold slammed the northeastern United States on Tuesday, grounding 3,000 flights, shutting down governments and schools and making travel a potential nightmare for millions. States across the northeast declared emergencies and warned residents not to travel during the fast-moving storm, which packed a potentially lethal combination of snow and wind, backed by temperatures up to 30 degrees Fahrenheit (17 degrees Celsius) below normal. The system could dump as much as a foot of snow on southern New England and to snarl the evening commutes of millions along the I-95 highway corridor from Boston to Washington, said Bruce Sullivan, a senior meteorologist at the National Weather Service. "Behind this system is a lot of strong winds, (with) very cold, bitter temperatures, so this snow is going to be around for a while," said Bruce Sullivan, senior meteorologist with the National Weather Service. He warned that stranded travelers faced potential frostbite or worse. "That's the risk you take if you travel in this kind of weather," Sullivan said. Hundreds of thousands of federal workers in Washington were ordered to stay home. City schools and offices also shut down, and the White House called off its Tuesday press briefing. But the Supreme Court remained open to hear cases, and organizers of the annual anti-abortion March for Life said Wednesday's rally would go on regardless of weather. About 3,000 airline flights in the United States were canceled, according to FlightAware.com, a tracking service. The bad weather left thousands of air travelers wondering when they were going to get home. "I rushed to the airport, but (my flight) just got canceled," said Sumeet Kapoor, 24, a North Carolina State University graduate student who was on his way from Washington's Reagan National Airport to Raleigh, North Carolina. "I actually had a class at 6, but I'm going to be late, I guess," he said. Hours after he was sworn in to a second term, New Jersey Governor Chris Christie declared a state of emergency, as did Delaware Governor Jack Markell. Christie's inauguration party on Ellis Island in New York Harbor was canceled because of the looming storm. In Massachusetts, Governor Deval Patrick postponed his annual state of the state address because of the weather. State governments in Delaware and Maryland shut down and Connecticut sent nonessential state workers home beginning at 3 p.m. The Maryland Transit Administration cut back rail and bus services. In Connecticut and Virginia, state officials warned residents not to travel if they did not have to. Some schools in North Carolina closed early, and schools were shut across Virginia and West Virginia. Connecticut closed all its schools for Wednesday, and Hartford, the state capital, sent students home early on Tuesday. At a gas station in Princeton, West Virginia, residents said they were stocking up on propane, food and other staples in case they lost power and had to weather the storm. The snow by itself isn't a threat. It's when it freezes after and weighs down the power lines that I get worried," said Jim Mullins, who spent the day buying supplies. Forecaster AccuWeather said the cold front would drop temperatures below freezing as far south as northern Florida. While the polar front grips the eastern United States, the western half will see above-average temperatures as a drought worsens, the National Weather Service said. Sullivan, the meteorologist, said the cold snap would be followed by two more polar fronts through the weekend. One would hit the Great Lakes region, and the other the upper Great Plains, he said. Reporting by Ian Simpson, additional reporting by Lawrence Hurley, Lacey Johnson, Colleen Jenkins, Edith Honan, Susan Healey, Scott Malone, Lacey Johnson, Ann Moore, Gary Robertson and Richard Weizel; editing by Eric Walsh, Chizu Nomiyama and Nick Zieminski