The Northeast is bracing for a monstrous winter storm that could trigger massive power outages and slam the brakes on air traffic and rush hours from Philadelphia deep into New England.

About 29 million people are under a blizzard warning and another 11 million in a winter storm warning, according to the National Weather Service.

New York City could see up to 20 inches of snow.  Parts of New England could see 2 feet or more.  High winds could cause whiteout conditions, and bring down power lines.

New York Mayer Bill de Blasio said "this could be the biggest snowstorm in the history of this city."  "My message for New Yorker's is prepare for something worse than we have ever seen before."