Snow piled up rapidly in parts of the northeastern United States as a blizzard swept in, forcing airlines to ground flights and schools to cancel classes while shrouding an early herald of spring, Washington's famed cherry blossoms, in ice.
The National Weather Service (NWS) warned some 50 million people from Pennsylvania to Maine of a "rapidly intensifying nor'easter" that was unusual for so late in the winter and many heeded the advice by staying home.
But the NWS also sharply dialled back forecasts in some areas, notably in New York City, where residents had been warned to steel themselves for potentially record-breaking wintriness.
Still, some in the region could expect to find themselves surrounded by up to 2 feet (60 cm) of snow by early Wednesday, the weather service predicted, with the worst blizzard conditions forecast for parts of New England.
The region could expect to find themselves surrounded by up to 2 feet (60 cm) of snow by early Wednesday
Governors in New York, New Jersey, Pennsylvania and Virginia declared states of emergency. New York's Andrew Cuomo suspended above-ground portions of the city's subway service and said the Metro-North commuter service to the suburbs would shut down at noon. Transit officials warned that more bus and train routes might be suspended throughout the day.
"There's no real reason to be on the roads," Cuomo said in an interview with MSNBC.
New York City was expected to escape the worst of it after the NWS withdrew its blizzard warning and roughly halved its snowfall forecast for the city to between 4 and 8 inches (10 and 20 cm).
Still, life was disrupted for many New Yorkers.
"It's a ghost town," Ali Naji, 33, said as he sat listening to Mexican pop music amid the emptiness of his usually bustling convenience store in Brooklyn's Fort Greene neighborhood.
His morning commute was easy enough since he lives upstairs. "I drop a rope and come down," Naji said, laughing, but added that he could see why others would be deterred. He gestured out the window, where an occasional pedestrian could be seen trudging in an umbrella-forward stoop against the wind and sleet.
In Brooklyn's Bedford-Stuyvesant neighbourhood, Lisa Luna, 36, and a friend walked around, hungry for breakfast.
"We weren't prepared for the blizzard and didn't go shopping," she said. "I just needed a bagel."
AIR TRAFFIC SNARLED
Airlines cancelled about 5,700 flights across the United States, according to tracking service FlightAware.com.
American Airlines cancelled all flights into New York's three airports - Newark, LaGuardia and John F. Kennedy International Airport - and JetBlue Airways reported extensive cancellations.
Delta Air Lines cancelled 800 flights for Tuesday for New York, Boston and other northeast airports. United Airlines said it would have no operations at Newark or LaGuardia.
New York City public schools - the largest US school system - cancelled classes on Tuesday as did schools in the Washington, D.C., area, Boston, Philadelphia and northern New Jersey.
In Washington, federal agencies were opening three hours later than normal after forecasters predicted 5 inches (13 cm) of snow.
At the open-sided Thomas Jefferson Memorial, the ice-slick marble floor served as a skating rink for some of the 71 eighth graders visiting from St. Mary's Academy in Englewood, Colorado.
Nearby, scores of cherry trees in early bloom, a tourist attraction and an emblem of springtime in the capital, were encased in ice.
The storm comes near the end of an unusually mild winter along much of the East Coast, with below-normal snowfalls.
In Boston, Kelley Peace, a 26-year-old dog walker, was out with three of her charges in the Beacon Hill neighborhood, where residents were braced for up to a foot of snow.
"The dogs are more hyper in this weather," she said. "They want to play. "Especially the big dogs. The only thing is the salt. It burns their paws. So I put booties on them."