A "potentially historic" blizzard could dump 2 to 3 feet (60 to 90 centimeters) of snow on a large part of the US Northeast, crippling a region that has largely been spared so far this winter, the National Weather Service said. More than 1,500 cancelled flights were expected.
A blizzard warning was issued for New York and Boston, and the National Weather Service said the storm would bring heavy snow and powerful winds starting Monday and into Tuesday.
"This could be a storm the likes of which we have never seen before," New York City Mayor Bill de Blasio said at a news conference.
De Blasio held up a piece of paper showing the city's top 10 snowstorms and said this one could land at the top of a list that goes back to 1872, including the 26.9 inches (68.3 centimeters) that fell in 2006. "Don't underestimate this storm. Prepare for the worst," he said as he urged residents to plan to leave work early Monday.
Around 1,700 flights scheduled for Monday are expected to be cancelled, according to the flight tracking site FlightAware. The storm promised treacherous travel by both land and air throughout the busy northeast corridor.
Boston was expected to get 18 to 24 inches (45 to 60 centimeters) of snow, and Philadelphia could see 14 to 18 inches (35 to 45 centimeters), the weather service said. The Washington, D.C., area was expected to get a coating or a bit more.
In New York, transit officials planned to use modified subway cars loaded with de-icing fluid to spray the third rail that powers trains.