A snowplough travels down a city street during heavy snow in the financial district of Manhattan, New York, on Monday. (Agence France-Presse)
A winter storm pounded the northeastern United States on Monday hitting tens of millions of people and forcing the rare cancellation of Broadway shows in New York.
Winter storm Juno is expected to dump up to three feet of snow in parts of the northeast, with the worst affected areas likely to be New England, particularly Connecticut and Massachusetts.
More than 6,560 flights were cancelled, the New York city transit system was to shut at 11pm, local time, and road travel made a criminal offense in 13 counties of the New York state.
Residents across the region rushed to supermarkets to stockpile food and essential items, as commuters rushed home to hunker down.
"It could be a matter of life and death, and that's not being overly dramatic, so caution is required," New York state Governor Andrew Cuomo warned.
States of emergency were declared in New York and New Jersey and a travel ban imposed in Connecticut.
New York's famed Broadway and top music venues - including Carnegie Hall and the Metropolitan Opera - shelved performances. National Basketball Association games were also postponed.
Heavy snow buffeted the region but Juno was expected to escalate into a major storm with poor visibility and dangerous winds overnight that will paralyze swaths of the East Coast.
As well as blizzard warnings, flood warnings are also in effect, with officials warning against power outages and falling trees.
Commuters' nightmareMr Cuomo called out several hundred National Guard for New York and Long Island, which juts out into the Atlantic and where he said wind gusts would reach up to 70 miles per hour.
Commuters poured out of Manhattan offices early, packing out stations as trains laid on extra services to get people home as visibility deteriorated dramatically during the afternoon.
Mr Cuomo said the entire New York city subway, rail and transit system would close at 11:00 pm and a travel ban would be imposed in 13 counties until further notice.
Those caught out on the roads after the cut-off point would be liable for fines of $1,300, Cuomo said.
Officials said virtually all flights at New York's LaGuardia airport would be cancelled today and that John F Kennedy International Airport would also see significant cancellations.
Boston's Logan International Airport will see no flights from Monday evening to Wednesday afternoon, reports said.
New York and New Jersey authorities compared emergency measures with those taken for Hurricane Sandy in 2012, which killed more than 200 people and caused months-long power cuts.
New York Mayor Bill de Blasio said it would be "most likely to be one of the largest blizzards in the history of New York City."
Record snowfall in the city of New York was 26.9 inches following a 16-hour storm in February 2006.
United Nations closes"Recognize this as an emergency," Mayor de Blassio cautioned. "You can't underestimate this storm. It's not a typical storm, its going to pack a real punch."
Schools will be closed on today and scheduled examinations cancelled.
The United Nations closed its headquarters early and was to remain shut, forcing the cancellation of an important event to commemorate the 70th anniversary of the Holocaust today.
Meteorologists said the storm would bring crippling conditions and warned that 28 million people were in the possible blizzard zone.
Chris Christie, a probable Republican candidate for the White House in 2016, said state offices would be closed for non-essential staff and warned that transit systems were unlikely to work today.
"We've had Hurricane Irene, Hurricane Sandy. For better or for worse, we know how to deal with these situations," he said.
The heaviest snow is likely to be in New England. Thunder and lightning could also accompany the heavy snow, meteorologists said.
Mr de Blasio said New York had deployed more than 1,800 snowploughs, and would have 40 per cent more ambulances and 500 more firefighters on duty to cope with the crisis.