(Updates with quotes, details on flight cancellations)
By Elizabeth Dilts and Scott Malone
NEW YORK/BOSTON, Jan 2 (Reuters) - The first major winter storm of 2014 bore down on the northeastern United States on Thursday with heavy snow, Arctic temperatures and strong winds that snarled travel just as many people were returning from holiday breaks.
The wide storm system stretches from the lower Mississippi Valley to the Atlantic coast, with parts of New England including Boston bracing for as much as 14 inches (36 cm) of snow by Friday morning. Some cities along the storm's southern edge expect only minimal snowfall.
Snow was falling across much of the northeastern United States on Thursday, with the serious accumulation expected to begin after sunset and continue overnight, said Kim Buttrick, a meteorologist with the National Weather Service in Taunton, Massachusetts.
"The real action is going to get cranked up this evening and during the overnight hours. We'll have heavy snow, windy conditions, reduced visibilities," Buttrick said, adding that dangerous cold would continue into Friday.
Forecast snowfall varied widely, with Washington expected to see under an inch (2 cm), Philadelphia and New York 4 to 8 inches (10-20 cm), Hartford 6 to 10 inches (15-25 cm) and Boston 8 to 14 inches (20-36 cm).
The storm is expected to snarl traffic on the I-95 highway corridor between New York and Boston, the weather service said. Coastal flooding was forecast along low-lying parts of New England.
The storm posed the first major challenge to the administration of New York's new mayor, Bill de Blasio. Problems from digging out from snowstorms have been political havoc for mayors in the United States' biggest city for decades.
"We have to get it right. There is no question," de Blasio told reporters. "Before I even think of politics or anything else, this is our job."
Some New Yorkers expressed confidence in their new leader's ability to handle a storm.
"I think he can pull it off. He seems like a hands-on person who can identify with what people in these communities are going through," said Wayne Jenkins, 40, who works at a senior center in the New York borough of Brooklyn.
The powerful storm forced about 1,697 U.S. flights to be canceled and about 3,964 delayed, with the worst-affected airports Chicago's O'Hare International and Newark's Liberty International Airport, according to FlightAware, a website which tracks air travel.
New York's three major airports were preparing to accommodate stranded travelers whose flights were canceled.
"We have a few hundred cots at each of the airports should you decide to become an overnight guest," said Thomas Bosco, an official with the Port Authority of New York and Jersey, at New York's LaGuardia Airport. The authority also runs Newark and John F. Kennedy International Airport.
Officials with Boston's Logan International Airport said they expected airlines to scale back operations during the storm, with the last departure expected at roughly 8:30 p.m. ET (0130 GMT).
One traveler worrying that his Friday flight out of Logan could be delayed or canceled was Ruben Raskin, 23, of San Jose, California, who was in the area visiting his girlfriend.
"It kind of reminds me why I moved to San Jose after going to college out here," Raskin said.
Conditions in Boston were bad enough by afternoon that the "Frozen Fenway" winter carnival, featuring sledding and college ice-hockey at the baseball stadium where the Red Sox play, was canceled for Thursday and Friday.
'DANGEROUS' COLD EXPECTED
The weather service said the mass of Arctic air would drop temperatures to levels 20 to 30 degrees below normal, with record lows possible on Friday.
"Temperatures are expected to plummet tonight and tomorrow with wind chills dropping as low as 25 degrees below zero (F/-32 C)," said Massachusetts Governor Deval Patrick. "That is a very dangerous set of circumstances."
The low temperature in the contiguous United States on Wednesday was -43 Fahrenheit (-42 Celsius) at Embarrass, Minnesota, the weather service said.
Patrick told non-essential state workers to head home at 3 p.m. ET (2000 GMT) as did his counterparts in neighboring Connecticut. Both encouraged private-sector employers to consider releasing their staff early.
Slippery road conditions made driving a hazard in many storm-hit areas.
In Cleveland, Ohio, Chris Behm spent an hour trying to reach the vocational training center for developmentally disabled people where he works before calling the commute off and urging his 19 employees to stay home.
"It was terrible on all of the roads and there is more weather on its way," Behm said. "It just wasn't worth it to open and possibly kill someone."
While most New York-area schools were open on Thursday, some parents were bracing for the possibility their children would be home on Friday.
"It's tough with these storms because I end up using days off that I don't want to take," said Kristen Carson, who had taken the train into Manhattan from her home in suburban Montclair, New Jersey. "After the holiday, it's really kind of a pinch." (Additional reporting by Victoria Cavaliere, Marina Lopes and Scott DiSavino in New York, Daniel Lovering in Cambridge, Massachusetts, Ian Simpson in Washington, Kim Palmer in Cleveland and Mary Wisniewski in Chicago; Editing by Nick Zieminski and Andrew Hay)