Polar vortex to unleash dangerous cold blast in northeastern US

A quick but intense blast of Arctic air will barrel into the Northeast later this week to deliver quite a cold shock to the Northeast and neighboring Canada, AccuWeather meteorologists warn. The wave of freezing air will serve as a harsh reminder that it's still the dead of winter despite January producing temperatures of 5-15 degrees above average across the region.

"A shift of the polar vortex will be at the heart of the brief cold blast in the Northeast," AccuWeather Chief On-Air Meteorologist Bernie Rayno said. In this case, a small lobe of the feature will pivot quickly southeastward.

High temperatures tend to range from near 20 in northern Maine to near 40 in New York City and the mid-40s in southeastern Virginia during late January. Instead, temperatures have been poking as high as 15 degrees above those levels at times this month. However, the surge of Arctic air that will be colder than the outbreak at Christmastime is coming for New England and the eastern Great Lakes region, as well as portions of the central Appalachians and the mid-Atlantic region.

The outbreak in mid- to late December heavily focused on areas west of the Appalachians in the Central states. For the Northeast, as well as a large swath of eastern Canada, this will be an Arctic blast that will hit hard and fast.

Temperature departures from normal as of Jan. 31, 2023.

"There will be places that will be 30-50 degrees colder Saturday morning than they were Thursday afternoon," AccuWeather Senior Meteorologist Tom Kines said.


For example, in Boston, after a high near 40 on Thursday, temperatures there will dip to 10 below zero on Saturday morning. If the temperature gets that low, it will shatter the daily record of 2 below zero set 127 years ago in 1886. A high in the single digits is likely on Saturday, forecasters say.

In Caribou, Maine, following a high of 20 on Thursday, temperatures will start the day on Saturday at 28 degrees below zero. The record low is 30 below zero set in 1971. Temperatures are forecast to remain well below zero during the day on Saturday.

"At peak during the outbreak from late Friday to Saturday, AccuWeather RealFeel® Temperatures will plunge between 30 and 50 degrees below zero where many people live in central and northern New England and could plummet close to an unworldly 100 below zero on top of Mount Washington, New Hampshire," AccuWeather Senior Meteorologist Adam Douty.

People who will be spending any length of time outdoors should be prepared for the extreme cold, which can be dangerous for those with pulmonary conditions, experts warn. The risk of frostbite on exposed skin will be very high with the event from Friday night to Saturday.

Even though the harshest cold will be felt in northern New England, areas as far south as New York City and Washington, D.C., will feel the difference.

Temperatures reached the mid-50s on Monday in New York City, but it will feel like the Arctic early Saturday in Manhattan with a morning low of 6 and afternoon temperatures only in the lower 20s. RealFeel temperatures will dip below zero at times as the air is funneled between the concrete canyons, forecasters say. The record low temperatures in Central Park on Saturday morning is 3 set in 1918, if the wind ends up being more northerly, rather than northwesterly. A northerly wind tends to be the most efficient for funneling cold air down the Hudson Valley and right into Manhattan.

Farther south, temperatures may struggle to reach the 32-degree mark in Washington, D.C., on Saturday after starting the day off in the mid-teens.

AccuWeather meteorologists will continue to track a series of storms that will bring a substantial amount of ice, travel delays and power outages to the South Central states during much of this week.

The combination of a slow-moving front and the northern edge of the southern U.S. storms has come through with small amounts of snow in the Interstate 95 mid-Atlantic region from Tuesday to early Wednesday. New York City had its first measurable snow (0.1 of an inch or greater) early Wednesday and other locations, such as Philadelphia and Washington D.C. were teetering on the edge of measurable snow.

The leading edge of the Arctic air has the potential to trigger a ground-whitening snow squall in parts of the Northeast from Thursday night to Friday. Such conditions in the past have led to sudden slippery conditions and near-zero visibility on the highways. Deadly chain-reaction accidents have occurred. AccuWeather meteorologists urge motorists to slow down and keep an eye out for rapidly-changing weather conditions.

The Arctic outbreak will set off bands of lake-effect snow but not in the Buffalo, New York, area as was the case in December. Instead some of the snow belt south of lakes Ontario and Erie will be on the receiving end of localized snowfall.

The cold blast will leave the Northeast as quickly as it arrives.

As an Alberta clipper storm travels across southern Canada, the wind direction will shift from the northwest to the southwest by Sunday afternoon, and temperatures will rebound.

"In many areas, temperatures will surge by 40 degrees on average compared to Saturday morning's frigid levels," Kines said.

Boston will climb into the lower 40s by late Sunday, which is slightly above average. In Philadelphia, after a Saturday morning low in the lower teens, temperatures will approach 45 on Sunday then soar to near 50 on Monday. The normal high in Philadelphia in early February is in the low 40s.

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