People walk up 5th Avenue at Central Park as it snows in the Manhattan borough of New York January 26, 2015. Winter Storm Juno has brought blizzard warning for New York and much of the North East United States. [Carlo Allegri / Reuters]

NEW YORK - The U.S. Northeast on Monday braced for a massive, crippling blizzard that could dump as much as three feet of snow as tens of millions of people were urged to stay home and airlines canceled thousands of flights.

Transit systems in New York, New Jersey, Connecticut and Massachusetts planned to curtail services, and several governors ordered motorists off roadways by evening in a region that is home to some 50 million people.

The National Weather Service issued a blizzard warning for New York City and surrounding areas between coastal New Jersey and Connecticut, beginning 1 p.m. EST (1800 GMT) on Monday and worsening overnight.

The weather service warned the approaching system would be a "crippling and potentially historic blizzard," with many areas along the East Coast expected to be blanketed by 12 inches to 24 inches (30-60 cm) of snow. The New York City area could be the hardest hit, with lashing winds topping 50 miles per hour (81 kph) and snowfall of three feet or more in some suburbs.

Vacationers and business travelers faced headaches as airlines canceled about 2,700 flights, according to flight-tracking service FlightAware, including nearly 700 flights at the three main airports serving New York City.

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.

N.Y. authorities said they were considering a total travel ban on main roads, starting at 11 p.m. EST (0400 GMT Tuesday).

"It could be a matter of life and death so caution is required," Cuomo said. "This is not an evening or a night to be out and about."