The Northeast Braces for the Worst Wind Chill in Decades

A brief shot of Arctic air and blustery wind will blast through the Northeast on Friday and into Saturday, producing perhaps the coldest wind chills in decades.

About a dozen daily cold temperature records across the region are likely to be broken over the next several days, primarily on Saturday morning, forecasters said. Winds gusting to 30 to 40 miles per hour, combined with air temperatures well below freezing, will make conditions extremely dangerous.

Forecasters with the Weather Prediction Center said some areas in northern New England could experience wind chills (the temperature the body feels when blustery winds remove necessary body heat) in the minus-50s.

“If wind chills fall to –40 or –50, this will be the first time in 20 or 30 years for many locations,” forecasters at the Portland, Maine, office warned.

In New York City, wind chills were expected to dip below zero.

On Thursday, officials were already warning residents about the coming cold.

In New Hampshire a blinking sign beside northbound Interstate 89 cautioned motorists of the coming plunge: “ARCTIC WIND CHILLS,” it read. “PLAN AHEAD.”

Atop Mount Washington, a 6,288-foot peak which is known for some of the world’s worst weather, a wind chill of –100 was predicted on Friday.

Ski mountains in northern New England were expecting lower turnout on Friday and Saturday, and some took precautions. Mike Hussey, general manager at Middlebury Snowbowl in Middlebury, Vt., said he planned to open the shorter chairlift at the 17-trail ski area on Friday — but not the longer lift, because of the risk of dangerous cold exposure. “Our level of comfort is a five-minute lift ride,” he said.

After a challenging season of warmer than normal temperatures and snow-making struggles, Mr. Hussey, a Vermont native, said the brief return to frigid cold felt notable mainly because of its brevity.

“Typically we would have a couple of weeks of these temperatures in January or February,” he said. “This is maybe 24 hours, and people are flipping out, when usually a deep freeze lasts two weeks.”

He added, “I don’t know that 24 to 30 hours is back to normal.”

In Boston, the public schools will be closed on Friday. Mayor Michelle Wu declared a cold emergency from Friday through Sunday and activated warming centers throughout the city. Wind chills as low as –27 were predicted there during the weekend.

In numerous locations, predicted wind chills could break records. In Caribou, Maine, which has been documenting weather conditions since 1948, forecasters are currently calling for wind chill readings to dip to -57, said Alex Lamers of the Weather Prediction Center. Caribou hasn’t seen a wind chill below –50 since 1988; the record was –59 in 1951.

The bitter cold is expected to begin on Friday morning when a pocket of cold air that has been sitting over Nunavut and the northern part of Hudson Bay in Canada since at least mid-January will shift into the Northeast, said Mr. Lamers. Temperatures will plunge throughout the day Friday.

Northern New York and most of Vermont, New Hampshire and Maine will likely see wind chills readings of –20 to –35 by sunrise Friday.

The core of dangerously cold air and winds will arrive Friday night and pass over the Northeast, especially northern New England. On Saturday morning, subzero air temperatures are forecast to spread across the rest of New York and New England, forecasters said. This will lead to wind chills of -40 to -60 across northern New England and -25 to -45 in eastern New York and Massachusetts.

The National Weather Service has issued specific alerts for various parts of the region, but the advice was broadly similar: Limit your time outdoors.

“Wind chills this cold, especially when they fall well below -30 degrees, can cause frostbite on exposed skin in 10 minutes or less,” Mr. Lamers warned.

In New York City, officials warned residents to use caution when operating space heaters. Last winter, a space heater sparked the fire at the Twin Parks apartment in the Bronx that killed 19 people.

Homeless shelters and food pantries across the city were also preparing for the cold. Lindsey Davis, senior director of crisis services for the Coalition for the Homeless, said her organization has been reaching out to homeless people about how best to navigate the conditions, especially those wary of sleeping in shelters because of safety concerns.

“A lot of people have a lot of experience keeping themselves safe outside, and so we want to make sure we’re talking about what the risks are,” Ms. Davis said. She noted that the city had drop-in centers for people to get warm.

Encore Community Services, which provides meals at a senior center and brings food to homebound New Yorkers, moved up its delivery schedule so staff and volunteers will not be outside on Saturday, said Judy Castillo, Encore’s chief operating officer.

While precipitation doesn’t appear to be a significant risk with this storm, Mr. Lamers warned that snow squalls could develop ahead of the cold air and could pose a danger to motorists.

Winds will die down throughout the day Saturday. And then, as quickly as the Arctic air mass moves in, it will move out.

Temperatures are expected to return to normal on Sunday.

Joshua Needelman contributed reporting.