Alaska News

Upside-down winter weather could be due to a wavering Arctic jetstream

The modern day wizards of weather know exactly why the climate conspired to unleash February rain and floods on Alaska -- a state once mocked across the nation as "Seward's Icebox," is now proclaimed as the climate-friendy "place to be" in the 21st century by The New York Times.

Blame an aberrant jet stream that has taken to swirling south from Asia into the Pacific Ocean tropics, where it grabs a load of warm, moist air and then heads north to deliver it to Alaska, with predictable results.

On Tuesday, the high temperature in Anchorage, the state's largest city, hit 40 degrees -- 11 degrees above the norm. The low was 30 -- 15 degrees above the norm.

The Anchorage Fur Rendezvous World Championship Sled Dog Races, a big deal in the 49th state, have been canceled for lack of snow. So, too, the Tour of Anchorage cross-country ski marathon. The 2,000-mile Iron Dog snowmachine race was roaring north to Nome through flooded forests and dirt-covered lowlands where the speeding sleds kicked up roostertails of dust.

Meanwhile, the Iditarod Trail Sled Dog Race, the sport's Super Bowl, has moved 260 miles north to Fairbanks -- located in the once-predictably frigid Interior of the state -- for its scheduled March restart.

It was raining there over the weekend, too. Rain in Fairbanks in February is as rare as snow in Florida. The long-term average temperature for the month in the Golden Heart City is 1.3 degrees below zero. That's right -- below zero. The 34-degree monthly high so far this year is almost 20 degrees above the normal high.

"Why is Alaska Warmer Than The Continental U.S.?" pondered The Weather Channel. The answer to that question is easy.

It's that jet stream gone crazy. Instead of proceeding normally across the globe in a general west to east direction, it has joined the unpredictable northern lights in dancing across the Arctic sky.

It wobbles south across Asia deep into the tropical Pacific Ocean and then comes charging north through the Gulf of Alaska to deliver a taste of Hawaii to the 49th state. Why exactly the jet stream is doing this is unclear, but there are scientists offering theories and a few predicting this jet stream "waver" could become the new norm.

A scientific paper published in the December issue of "Environmental Research Letters" links the change to global warming in the Arctic.

"The Arctic has warmed at approximately twice the rate of the Northern mid-latitudes since the 1990s owing to a variety of positive feedbacks that amplify greenhouse-gas-induced global warming," wrote study authors Jennifer A. Francis and Stephen J.Vavrus. "This disproportionate temperature rise is expected to influence the large-scale circulation, perhaps with far-reaching effects."

Among those "far-reaching effects" would be an Iditarod-free Alaska -- long the dream of some animal rights activists -- and a frozen continental U.S., because the waver that has warmed Alaska does the opposite to the rest of the country.

The jet stream flowing north through the 49th state pushes up into the Arctic, hits a wall of cold air, grabs some of that and ricochets south to bombard the East Coast of the U.S. with cold and snow. East Coast skiers and snowboarders shredding the Appalachian Mountains should be thanking their depressed Alaska counterparts

"'Snow, Snow, Snow,' and East Coast Skiers Rejoice,'' The New York Times headlined on Monday.

"As back-to-back snowstorms have engulfed the Northeast over the past three weeks, taxing the area's collective shoveling strength, ski resorts in Vermont and New Hampshire have witnessed a curious phenomenon for New England: powder. And lots of it," the newspaper reported. "As of Feb. 23 more than 261 inches of snow has fallen at the Jay Peak Resort in Vermont Stowe and Stratton have gotten 225 and 144 inches, respectively; and at Cannon Mountain in New Hampshire, three feet of snow accumulated in the first half of February alone."

Meanwhile, Alyeska Resort in Girdwood, Alaska's largest skiing spot, was reporting only 6 inches of snow left at the base Wednesday after a series of rainstorms.

Alaska skiers of all sorts are depressed. The state ski championships were held at Kincaid Park in Anchorage in the rain over the weekend. Umbrellas were an unexpected necessity for spectators.

And even nonskiers are finding themselves getting depressed by the weather. Think of an even darker, wetter, chillier Seattle in winter, and you've got a mental picture of Anchorage lately.

The conclusions of Francis and Vavrus aren't likely to make Alaska skiers feel any better; they concluded the jet stream waver could be getting more likely than less so going forward.

The results of their research, they wrote, "reinforce the hypothesis that a rapidly warming Arctic promotes amplified jet-stream trajectories, which are known to favor persistent weather patterns and a higher likelihood of extreme weather events. Based on these results, we conclude that further strengthening and expansion of AA (Arctic amplification) in all seasons, as a result of unabated increases in greenhouse gas emissions, will contribute to an increasingly wavy character in the upper-level winds, and consequently, an increase in extreme weather events that arise from prolonged atmospheric conditions."

In other words, Alaskans might be better advised to invest in umbrellas and Gore-Tex than skis and snowmachines.

Craig Medred

Craig Medred is a former writer for the Anchorage Daily News, Alaska Dispatch and Alaska Dispatch News. He left the ADN in 2015.