Tens of millions of people from North Carolina to Massachusetts are bracing for a major winter storm that could dump up to two feet of snow on some regions starting midday Wednesday.
"This is going to be a serious storm — and people need to take it seriously," New York City Mayor Bill de Blasio warned at a briefing Tuesday.
Parts of the city could see as much as a foot of snow, and communities to its north, as well as northern New Jersey and parts of Connecticut, may get even more than that.
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The New York City Dept. of Sanitation said in a tweet it had pre-deployed 700 salt spreaders and over 1,300 plow trucks that will soon begin to roll out across city.
The snowstorm could be the biggest New York City has seen in years, De Blasio said as officials, including the MTA, urged people to avoid traveling unless necessary.
A mostly-deserted Times Square was sprinkled with a light dusting of early snow as of 2:30 p.m. local time, according to a live EarthSky camera, while a thicker coating already blanketed streets outside Philadelphia's Franklin Institute.
Forecasters expect worsening snow and wind throughout the day Wednesday.
Massachusetts Gov. Charlie Baker urged residents to take caution while outdoors after what he described as a "very mild fall": "we clearly haven't had to deal with something like this in quite some time," Baker said.
The governor said Massachusetts is deploying 3,800 pieces of snow clearing equipment ahead of the storm across 15,000 miles of roadway.
"It would be great if you could just stay put and let the road crews do the work that they need to do," Baker said.
Those warnings were echoed as far south as North Carolina, where the state's emergency management agency urged drivers to use caution if they must be on the roads.
New Jersey Governor Phil Murphy on Wednesday declared a state of emergency for the Garden State beginning at 2 p.m. and ordered most state offices to close at 1 p.m.
"This will be a statewide weather event and every county is currently under either a watch or a warning of some sort," Murphy said, adding that strong winds are expected in the southern coastal regions that do not expect much snow accumulation.
Gusty winds and possible thundersnow could cause whiteout conditions and power outages across the region.
Snow is expected to continue falling in New England throughout Thursday morning, with most of the East Coast's precipitation ending by sunset Thursday.
Ahead of the storm's arrival in the northeast, forecasters said that a region stretching from Maine to Virginia could expect between three to six inches of snow accumulation.
North Carolina and Virginia faced an icy, wintry mix Wednesday morning, with temperatures hovering just above freezing around midday.
Overnight Wednesday, snowfall rates of up to 3 inches per hour are possible in the New York City metropolitan area. Just south of Albany and in south-central Pennsylvania, up to 24 inches of total snow accumulation is possible, according to the NBC News Weather unit.
Government meteorologists in Albany noted that if forecasts are correct, December 17 could break its previous 1970 eleven-inch record for snowfall.
Northwestern Virginia could get snow and sleet and up to a quarter-inch of ice, according to the National Weather Service, and Maryland activated a statewide response for a storm that could see a foot of snow in Hagerstown.
In Boston, forecasters are calling for up to a foot of snow, which is expected to start falling around sunset Wednesday.
New York City's weather service office predicted snow Wednesday afternoon and into Thursday morning.
Pennsylvania Gov. Tom Wolf signed a proclamation of a disaster emergency ahead of the storm, which authorizes state use of resources and purchases.
Central Pennsylvania might get as much as 24 inches of snow, forecasters said Wednesday morning.
Pennsylvania, like other states, is distributing a Covid-19 vaccine, and state officials say they are prepared to deal with any impacts from the storm and to keep roads clear.
"There's actually something simple that every Pennsylvanian can do to help us all get through this storm as quickly as possible," Wolf said. "And that is: Stay home, if you can."
Road conditions worsened in Pennsylvania on Wednesday evening as heavier snowfall passed through the area. An estimated 1 inch of snow per hour could cover even treated roads, according to NBC affiliate WPXI.
Video posted by the emergency services of Collier Township, just west of Pittsburgh, showed a truck running directly into a response vehicle as a crew was attending to a car accident.
"This is a reminder to please SLOW DOWN and use CAUTION not only in this weather, but ALL the time," the post said. "Two of our members were almost struck during this incident, please be careful."
Some Keystone State residents, however, say they hope the pandemic won't have an impact on a winter school tradition: snow days.
Upper Dublin parent Rachel told NBC Philadelphia she's happy that her school district already scheduled snow days into the calendar.
"I think we should have snow days," Rachel said, "because kids need to be kids."
Schoolchildren in the nation's largest school district have no such luck.
"I know we all grew up with the excitement of snow days, but this year is different," New York City Mayor de Blasio wrote on Twitter midday.
"Tomorrow will be a FULL REMOTE learning day for our students."