The first nor'easter of 2021 is threatening a possible two feet of snow in New York City and other parts of the mid-Atlantic and Northeast.
The combination of heavy snow, gusty winds and coastal flooding was expected to make travel dangerous to impossible in much of the region Monday and could knock out power over a wide area.
"Make no mistake: this storm will bring heavy snowfall, and it will make travel dangerous in every neighborhood in our city," New York Mayor Bill de Blasio said in declaring a state of emergency until 6 a.m. Tuesday. "New Yorkers should stay home, keep the roads clear for emergency vehicles, and let our plows work to keep us all safe."
In Central Park, 5.3 inches of snow had fallen by early Monday -- more than the city saw during the 2019-20 winter, when 4.8 inches fell. CNN meteorologists say it's possible around two feet of snow will blanket the city before the storm ends.
On the five-tiered scale used by the National Weather Service, New York City could see level five, or extreme impacts. Near blizzard conditions are expected into Monday night, with gusts of 35-40 mph. The storm may not let up until Wednesday morning.
COVID-19 clinics in New York, New Jersey, Philadelphia and other locations in the region were closed on Monday because of the storm.
New Jersey's governor, Phil Murphy, also declared a state of emergency, closing all state offices and the New Jersey Transit system.
"Heavy snow, coastal flooding, and high winds are expected in many parts of the state," Murphy said. "The safety of residents and workers is our utmost priority. Please follow all weather-related guidance and stay off the roads in order to allow access for emergency personnel."
Highways are already treacherous. All eastbound lanes of I-80 in Hope Township, New Jersey, were closed after a tractor-trailer jack-knifed.
The storm snarled air traffic, too.
More than 1,300 flights across the United States were preemptively canceled ahead of the nor'easter and, by Monday morning, the number of canceled flights within, into, or out of the United States had risen to more than 1,600, according to Flightaware.com.
Major hubs such as LaGuardia, Newark and JFK were reporting 70% to 80% of Monday's scheduled flights as canceled.
The hard-hit places
New York City
The snowfall, which began late Sunday night, picked up intensity Monday, and snowfall rates could get as high as 1 to 3 inches per hour for the city, Long Island and southern Connecticut. That could create zero-visibility conditions and make travel very dangerous.
MTA buses are operating on a reduced schedule on Monday and the Long Island Railroad is running on a weekend schedule. No empty or tandem tractor trailers are allowed on bridges, and pedestrian walkways on some bridges are closed.
The region might experience "thundersnow," which is rare, in the strongest snow bands in this region.
The storm could drop up to 21 inches by the time it ends Tuesday morning. If that happens, it will be the most snow New York City has seen since the January 22 to 24, 2016, storm that dumped 27.5 inches over a two-day period. It would also cement this storm as one of the most prolific winter storms for the city, placing it in the top 10 of largest snowfall totals on record.
The city has already seen 2-3 inches of snow, ending a run of 710 consecutive days without an inch of snow or more, the second longest in the city's history going back to 1884. On Monday, the precipitation transitioned to a sleet and snow mix, coating roadways with ice and adding to driving danger. There's a chance of some light snow on Tuesday morning before it ends in the afternoon. The district could see a total of 5 to 7 inches, the most in the last two years.
A similar combination of rain and snow hit Philadelphia, where 2 to 3 inches of snow had fallen by Monday morning. A rain-snow mix in the morning will likely switch back to snow Monday night through Tuesday. A final total expected there will be around a foot.
A winter storm warning is in effect and the city issued a snow emergency. Eight to 12 inches of snow is forecast, with even more inland. Snow will be heavy Monday afternoon with 4 to 6 inches by Monday evening.
A wintery mix beginning Monday night will continue all day Tuesday, changing back to all snow Tuesday night. The National Weather Service said road conditions will deteriorate quickly around midday Monday as the heaviest snow arrives.
Boston is accustomed to significant snowfall, having alerted crews to plow 2,000 lane miles of the city's roadways through Tuesday.
That's equivalent of the distance from Boston to Denver being cleared of snow in under 48 hours.
The placement and track of this multiday storm will play major role in the snowfall totals across the Northeast. A storm close to the coastline will produce more rainfall, while one too far offshore will reduce moisture and lead to less snowfall.
Models suggest this nor'easter should be in the sweet spot for abundant moisture leading to significant snowfall. Another important factor has also been in play, increasing the confidence for the impacts of the storm.
According to CNN meteorologist Tom Sater, this storm is tapping cold Canadian air. "A strong high pressure system is in place over southeast Canada, pushing plenty of cold air far south enough and lasting long enough to get the kind of snowfall being forecast."
Nearly 75 million across a dozen states are under some kind of winter watch or warning from a storm which had its genesis in the Midwest Saturday. While there, the storm dropped more than foot of snow in Milwaukee.
Metro Chicago, with 10.5 inches, saw the most snow since 2018. Official snow totals from the National Weather Service ranged from 1 inch to 13 inches so far in the Midwest.
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