NEW YORK (NewsNation Now) — Snowfall picked up Monday in the Northeast as the region braced for a storm that could dump well over a foot of snow in many areas, create blizzard-like conditions and cause travel problems for the next few days.

NewsNation Chief Meteorologist Albert Ramon said the nor’easter developing off the Atlantic coast will be a “slow mover.”

“It’s pulling in cold air from Canada and it’s working from that moisture from the west, but it’s also pulling in moisture from the Atlantic Ocean,” said Ramon.

Snow has already made its way across Pennsylvania, the southern portion of New York, Connecticut and New Jersey.

With flakes falling since Sunday evening, the National Weather Service said more than 13 inches of snow had fallen in Manhattan’s Central Park as of 1 p.m., and as much as 16 inches was reported in northern New Jersey. Although the heaviest parts of the storm had moved through the metropolitan area by Monday evening, lighter snow showers were expected to continue virtually all day Tuesday, forecaster James Tomasini said.

“We’re looking at a long two days here,” New York Gov. Andrew Cuomo said at a virtual news conference.

The National Weather Service warned, “when the power goes out in the winter, the cold can be deadly,” and issued guidance on how to stay warm in an emergency.

In Pennsylvania, authorities said a 67-year-old woman with Alzheimer’s disease who reportedly wandered away from her home was found dead of hypothermia on an Allentown street Monday morning. About 60 miles north in Plains Township, a shooting that followed an argument over snow removal killed a married couple, and the suspect was later found dead at his nearby home of a wound believed to have been self-inflicted, officials in Luzerne County said.

A preliminary investigation indicates the people involved had a long-running conflict, but “this morning, the dispute was exacerbated by a disagreement over snow disposal,” District Attorney Stefanie Salavantis said.

It was already impacting coronavirus vaccinations in New York and New Jersey, with some appointments for Monday needing to be canceled and rescheduled. In New York, some appointments for Tuesday have already been canceled or rescheduled, according to New York State Spokesperson Jack Sterne.

“There’s going to be tremendous danger and difficulty getting around on Monday,” de Blasio said Sunday at a press conference. “The last thing we want to do is urge our seniors to come out in the middle of a storm like this.”

The storm could paralyze New York City, which was forecast to be at the center of the Nor’easter’s bluster.

“This is already the biggest snowstorm for New York City in five years — at least five years — and it’s still snowing there,” said Ramon.

All flights at New York’s LaGuardia airport were suspended Monday morning due to the snowstorm, the airport said. Aboveground New York City subway service was due to stop at 2 p.m.

New York Mayor Bill de Blasio said during a Monday press conference that in-person learning for the city’s public school system would be cancelled Monday and Tuesday.

The NWS advised that “treacherous” travel conditions are expected throughout the northeast for a few days, as wind gusts of up to 50 miles per hour are forecast for Monday, creating blinding, blowing snow.

As of Monday morning, some areas had already gotten 3 to 5 inches of snow, with 6 inches in parts of Pennsylvania, she said. In parts of New Jersey, 7 inches already was reported as of Monday morning.

New Jersey Gov. Phil Murphy on Sunday declared a state of emergency in order to deploy resources. He also closed all state government offices for nonessential personnel and the state’s six mega sites that distribute COVID-19 vaccines.

All New Jersey Transit trains and buses were suspended, except for the Atlantic City Rail Line. New York Waterway ferries also were suspended. Amtrak modified its train service, canceling some trains. More than 1,500 people were without power on Monday morning. However, high winds are likely to knock out power to customers people across New Jersey heading into Tuesday.

The storm disrupted the second phase of Massachusetts’ vaccine rollout as a Boston site that was supposed to open Monday for residents ages 75 and over did not; some other mass vaccination sites were open. The state was expected to get 12 to 18 inches of heavy, wet snow and wind gusts of up to 55 mph along the coast, according to Gov. Charlie Baker.

“We’re used to dealing with snow this time of year, but it’s important for folks to take this one seriously due to the heavy snowfall, the high winds, and the speed with which this snow is going to fall when it starts to come down,” Baker said at a press conference.

In Rhode Island, all state-operated COVID-19 testing sites will be closed on Monday, the state Department of Health said.

In recent days, a storm system blanketed parts of the Midwest, with some areas getting the most snow in several years. Ohio, Washington, D.C., and parts of Virginia also received snow.

In anticipation of the storm, Washington D.C., Mayor Muriel Bowser on Saturday declared a snow emergency in effect from Sunday to Tuesday morning.

Video from the National Mall shows heavy snowfall obscuring the Washington Monument, as well as the Lincoln Memorial.

The snow and cold in Washington led President Joe Biden to postpone a visit to the State Department that had been planned for Monday.

White House press secretary Jen Psaki said the administration had been in contact with governors in states affected by the weather.

The storm system blanketed parts of the Midwest in the most snow some places had seen in several years. Chicago got almost 7 inches of snow by Sunday morning, leading to the cancellation of a couple of hundred flights at the city’s two airports. In Wisconsin, snow depths in some counties near Lake Michigan had reached more than 15 inches, and the snow was still falling.