Pittsburgh Post-Gazette

ALASKA COLD

Despite Alaska’s overall warming, the state is in a cold snap.

- By Matthew Cappucci

The temperatur­e in Bettles, Alaska, hasn’t climbed above 0 degrees in nearly 10 days. Sunday’s high was minus-47. And at minus-56 degrees Friday morning, the quiet community of roughly a dozen yearround residents set a daily record low. The frigid temperatur­e rivaled the average winter temperatur­es found on the surface of Mars.

Bettles is not alone. Much of Alaska’s interior and far north are enduring lows of 35 to 55 degrees below zero. During the daytime, it doesn’t get much better. Highs of around minus-40 are pretty common.

Fairbanks, meanwhile, was forecast to “warm” into the minus-20s on Friday, with a chance of snow flurries and freezing fog.

The cold is courtesy of an encroachin­g, strong dome of high pressure banked to the west of Alaska, while a series of lows looms to the east. The flow of air between these two weather systems has allowed a persistent tongue of cold to sweep down from the Arctic, lapping at the frigid tundra. Clear skies induced by high pressure has permitted radiationa­l cooling, plummeting temperatur­es even more.

Elsewhere in Alaska, Kotzebue started their day at minus-15, Anaktuvuk Pass at minus-27, and even Utqiagvik — the United States’ northermos­t community — ended their work week at a brisk minus-11.

Temperatur­es will finally start to moderate some into the weekend, recovering toward more seasonable norms to ring in the new year. However, there are indication­s the pattern thereafter will favor renewed shots of Arctic air.

Cold of this magnitude is not that unusual for Alaska, although it’s actually becoming more rare as the climate warms. Bettles, for instance, averages 11 nights a year that drop below minus-40.

However, in 1950, Bettles averaged closer to 20 nights a year with minus-40 degree lows.

It’s not an isolated trend.

Across Alaska, the frequency of ultra-cold nights has been dwindling in recent years. In most places, they’re about a third less common. Alaska is warming faster than any other state in the country. Climate Central, a nonprofit climate research and journalism organizati­on, estimates the nation’s largest state has spiked by more than 4 degrees just since 1970, rapidly melting ice and redefining life for Alaska residents.

Thus far, it appears the only temperatur­e records set or tied were in Bettles. Other weather stations may technicall­y have set record values, but longrunnin­g weather and climate observatio­ns are only available at 20 different sites across the state.

Allakaket did hit minus60 Friday morning, the state’s coldest observed temperatur­e during this Arctic outbreak. And yet it still didn’t even claim a local daily record. The village northwest of Fairbanks had dropped to minus-67 degrees on Dec. 27, 1954.

Alaskans also are dealing with ice fog. In the Lower 48, there’s freezing fog, which occurs when supercoole­d water droplets remain in the air at temperatur­es below freezing. These droplets freeze upon contact with objects — depositing an icy glaze on any untreated surface or vegetation. It’s a sneaky way to ice over the landscape.

Ice fog, however, is even more extreme.

“It only forms at 35 degrees below or lower,” explained Alex Young, a meteorolog­ist at the National Weather Service in Fairbanks. “All the particulat­es are actually frozen.”

Because the air can hold so little moisture, any additional moisture at temperatur­es near minus-50 immediatel­y results in ice fog.

The ice fog is most common near population centers. That’s because it’s so dry up there that most of the moisture in the air comes from human activity — automobile­s, generators, or even breathing. At temperatur­es this frigid, that moisture freezes and lingers. A walk to the mailbox could technicall­y deposit a floating ice cloud behind you.

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