The northeastern United States is steeling itself as Winter Storm Juno hits, with meteorologists predicting more than two feet of snow in the region stretching from New York to Boston.
A blizzard warning was issued covering 400km from northern New Jersey to southern Maine where about 40 million Americans live.
More than 5,000 flights were cancelled in one of the busiest air traffic regions in anticipation of heavy snowfalls that will, with hurricane-force winds and coastal flooding, cause havoc for residents.
State and city officials were preparing for widespread power cuts and travel disruptions.
Snow started flurrying in New York City early on Monday where the National Weather Service said that up to 20 inches could fall over Monday night and Tuesday morning. Residents in Boston and other parts of New England were bracing themselves for two feet or more.
There were long queues at supermarkets across the region as residents stocked up on food and other essential supplies.
"This literally could be one of the top two or three largest storms in the history of this city," said New York mayor Bill De Blasio.
“My message to New Yorkers is to prepare for something worse than we have seen before.”
Connecticut governor Dannel Malloy warned about "potentially a dangerous storm", urging residents to have a plan to get home on Monday night and ordering all vehicles off state roads after 9pm.
Boston's Logan Airport cancelled flights after 7pm on Monday and all day Tuesday.
"Don't panic. Let's get this thing right," said Boston mayor Marty Walsh.
Boston’s record for snowfall is 27.6 inches over two days in February 2003. The record in New York is 26.9 inches during a February 2006 blizzard.
State of Emergency
New York governor Andrew Cuomo declared a state of emergency and deployed National Guard troops to a number of counties in the southern part of the state, as well as New York City.
New York authorities said they were considering a total travel ban on main roads, starting at 11pm.
New York City subways, which carry 5.5 million riders daily, will run on a normal schedule until about 8pm, when service will be curtailed to allow subway cars and equipment to be stowed.
New Jersey governor Chris Christie also declared a state of emergency. New Jersey Transit commuter trains will stop running for at least one day, beginning at 10 pm on Monday.
The governors of Massachusetts and Connecticut told residents to expect driving bans. They also warned that hundreds of thousands of people could lose power, possibly for days.
Additional Reporting: Agencies
