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The wind chill at the summit of New Hampshire's Mount Washington dropped to minus-108 degrees Friday, marking what meteorologists and climate scientists say probably is the lowest temperature recorded in the history of the United States, as the Northeast is being battered with dangerously cold air.

Videos recorded by the nonprofit Mount Washington Observatory show how the extreme cold and strong winds of more than 100 mph from the Arctic air blast walloped the summit Friday afternoon, and made the mountain with the tallest peak in the Northeast seem like another planet. In fact, the eerie scene atop Mount Washington was slightly colder than the average on Mars this week, according to NASA.

The wind chill at Mount Washington, a 6,228-foot peak known for erratic weather, surpassed the record of minus-102.7 degrees noted in 2004. The observatory had forecast sustained winds of more than 100 mph on Friday night, with gusts around 128 mph.

The Mount Washington Observatory tweeted Friday afternoon that the daily record temperature set in 1963 had been broken and that temperatures were "expected to plunge even lower overnight." And they did just that, dropping to minus-108, according to the National Weather Service. (The Mount Washington Observatory calculated the wind chill at minus-109 degrees.)

"The 96 mph winds (gusts to 127 mph) are producing a wind chill of -108 F," the agency wrote Friday night.

A spokesperson for the Mount Washington Observatory did not immediately respond to a request for comment Saturday morning.

Artic blast

Mount Washington Observatory meteorologist Francis Tarasiewicz told WMUR-TV in Manchester, N.H., that the record wind chill had capped off "an amazing day, an awe-inspiring day and actually a bit of a frightening moment." Tarasiewicz noted that the strong wind, which he described as "a topsy-turvy whiplash," broke the hinge of a door at the observatory because of the force the blasting air exerted on it.

Frostbite

The meteorologist, who pleaded with hikers to stay off the trails on Saturday, warned that such extreme wind chills would result in frostbite on exposed skin in less than a minute.

"On some of my observations, there have been tiny little gaps in my mittens and the spot that was uncovered to the wind felt like a bee stinging my arm continuously," Tarasiewicz said.

The National Weather Service said the temperature at Mount Washington dropped as low as minus-46 degrees Friday night.

"Right now Mount Washington is living up to the reputation of having the worse weather in the world," the National Weather Service wrote on Twitter.

The record-breaking wind chill at Mount Washington is part of dangerous cold air invading the Northeast and putting nearly 50 million Americans in 15 states under wind chill alerts into Saturday. Parts of Maine are experiencing their most extreme wind chills in at least a generation, and New England cities including Boston, Providence and Bridgeport, Conn., set record daily temperature lows, according to the Weather Service.

Record wind chill

Brian Brettschneider, a climate scientist based in Alaska, tweeted that the last time the wind chill could have hit at least minus-108 in Mount Washington would have been 138 years ago. Using old climate forms showing the temperature and 24-hour average wind speed, Brettschneider estimated that Mount Washington would have seen a minus-108 wind chill on Januarry 22, 1885.

Meteorologists and weather experts across the country were blown away by the record wind chill.

"Mount Washington, New Hampshire, has experienced the most extreme weather on planet Earth today," wrote Colin McCarthy, a storm watcher based in California.

"Mind-blowing observations from Mount Washington," said Lee Goldberg, a meteorologist with WABC-TV in New York.

"Woah!" exclaimed Brandon Orr, a meteorologist with WPLG-TV in Miami.

Others on social media grappled with comprehending the extreme weather they were witnessing at Mount Washington.

"[The] Mount Washington summit looks like another planet," one observer tweeted.

As weather experts pointed out, Mount Washington found itself in the stratosphere Friday night as the result of a lobe of the polar vortex that barreled south. The atmosphere becomes more compressed as it cools, meaning that the boundary dividing its two lowest layers, the troposphere and the stratosphere, known as the tropopause, will sink in altitude.

That is what happened Friday night - said Terry Eliasen, a meteorologist with WBZ-TV in Boston, who noted on Twitter that the atmospheric heights were so low Friday that anyone above 4,000 feet, such as at the summit of Mount Washington - would be in a different atmospheric layer.

"This layer is typically 4-12 miles up, but tonight it will be less than a mile!" he tweeted Friday alongside a graphic projecting how low the stratosphere would dip.

By Saturday morning, there was good news and bad news for Mount Washington, according to the observatory.

The good news? The wind chill was no longer minus-108 degrees at the summit.

The bad news? The wind chill had improved only to minus-77 degrees.