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New norm

alyeska rain

A Friday screen grab from one of the webcams at the Alyeska Resort

Rain was falling in the Alaska ski-resort community of Girdwood on Friday afternoon, and the National Weather Service was predicting it would reach the state’s largest city by the weekend. 

 

After an unusually warm and snow-short Christmas season, the latest shift in the weather had more than a few residents of Anchorage wondering if their city really was on the way to becoming the new Seattle, albeit it one with even less winter sunlight. 

By the time night fell at 4:15, temperatures on the slopes of the Front Range Chugach Mountains about the city were already in the mid-30s as warm, moist air rolled in from the Gulf of Alaska to the south. 

All of this comes on the heels of December 2017 that started out frosty only to end up 7.5 degrees above normal in Anchorage for the month, and a rather startling 14.4 degrees above normal in the community of Bethel to the west.

After a string of winters like this, people are understandably starting to wonder whether the wet and warm is the new normal.

No one can say for sure. Climate is assessed not in years but in the averages of tens of years. But what climatologists have been saying about a new sea-ice hypothesis has to make one to wonder.

Ivana Cvijanovic and her colleagues at the Lawrence Livermore National Laboratory in California have suggested that an Arctic Ocean ice-free for longer and longer periods generates enough winter warmth to disturb normal, “high-latitude planetary wave patterns” resulting in a ridge of high-pressure air along the West Coast of North America.

Weather all along the coast then shifts, they write, due to the “consequence of a geopotential ridge in the North Pacific that steers the wet, winter air masses northward into Alaska and Canada….”

A “geopotential ridge” results from the pull of gravity on air in the atmosphere with heavier, dry air flowing from the atmosphere toward the ground and lighter, wet air rising from the planet’s surface.  This process creates ridges and troughs in the atmosphere, and those ridges and troughs play big roles in directing how weather moves around the globe as our ever-spinning planet hurtles through space.

You can think of the ridges and troughs a bumpers that bounce weather fronts around as they try, in general, to move west to east across North American.

Warm versus cold

Former Alaskan Karl Volz was thawing out Friday in Bangor, Maine, which had just emerged from a record cold snap with Maine residents now being warned to get ready for an ice storm. 

“We’ve got your weather,” Volz joked when reached by telephone.

Up until not long ago, Volz was the associate climatologist at the Alaska State Climate Center in Anchorage. Bangor shouldn’t have been much of a switch for him. Both communities have an average temperature of 17 degrees in January, though Bangor is somewhat warmer on average during the day when people are outside and somewhat colder at night, on average, when people are comfortably inside.

Or at least this is the way it used to be.

“We just had a period where every night was below zero” and daytime temperatures only crept into the teens, said Volz, who noted Maine’s problem was that it was in a “trough” while Anchorage was getting the curse or benefit of a “ridge.”

What one thinks of warm, winter weather in Alaska sort of depends on attitudes toward winter. For those who hate shoveling snow, this has been a perfect Alaska winter to date. For those, like Volz who love to ski, it hasn’t been that great.

Volz noted the once convenient base elevation of 250 feet at the Alyeska Ski Resort in Girdwood in now a resort liability.

Alyeska’s proximity to Turnagain Arm and the Seward Highway,  the resort is only three miles from tidewater, made Alyeska easy to get to when it was started in 1959. At the time, so much snow fell even a few hundred feet higher up the mountain that a higher base area seemed impractical, Volz said.

Now skiers are lucky to have a tramway to take them to near the top of the mountain and a midway chairlift so they can get above the rain for a day of skiing.

Alyeska still gets tens of feet of snow at the top of the mountain, but there is regularly rain at the bottom no matter the month. Volz is one of those who thinks this is something to which Alaska skiers might need to become accustomed.

“We really do seem to see that (Arctic) sea-ice feedback,” he said. “This is the new normal for California. They are getting ridged out.”

Granted, there are breaks in the pattern now and then. The deadly Santa Barbara flooding and mudslides this week resulted from a Pacific storm that made it onshore. But the ridging has been moving a lot of wet, Pacific storms that used to hit California north into Oregon, Washington state, Canada and, yes, even Alaska.

“There’s a lot more of a longitudinal flow,” Volz said.

A couple of degrees

Not that the change in flow necessarily dooms Alaska to rain.

Just a few degrees temperature difference can turn all that moisture into snow. Six years ago, Anchorage was buried in white fluffies with temperatures only a few degrees cooler than normal.

“It has been a boom season for snow removal contractors and auto body repair shops. Skiers enjoyed a season of plenty when it wasn’t windy, rainy or locked in a deep freeze of sub-zero temperatures,” National Weather Service climatologist John Papineau wrote after the Little Ice Age finally ended.

“….No matter how you look at it, this winter was white—not only in Anchorage but throughout Southcentral and across much of Alaska. Although the official snowfall measurement is taken in west Anchorage,” he added, “snow depth varies greatly across town. On the upper Hillside for example several locations have measured more than 200 inches of snow this season.”

Two-hundred inches is nearly 17 feet of snow. That is enough snow to fully bury some single-story homes. Some wondered if the end of global warming had arrived and then….

Papineau might have seen what was coming.  His summary of the winter underlined the vagaries of climate.

“It is apparent that this winter shares characteristics with previous big snow years—most snow came in small increments rather than in large doses, he wrote. “Astute readers will notice that three of the highest snowfall totals…have occurred in the last nine seasons. This begs the question whether we are experiencing an increase in snowfall or precipitation. There does not appear to be any trend in the data at this point, but it’s worth monitoring.”

And there was no trend, or if it was, it had very, very short-lived.

A series of snow-short winters followed 2011-12, and although the past winter had more snow than those previous, it was far from a record. The Iditarod Trail Sled Dog Race pretty much sums the history.

Because of a lack of snow, the race’s restart had to be moved north to Fairbanks in 2015 and 2017.  In 2014, the race went north on the normal, 1,000-mile trail from Willow, a small community in the Matanuska-Susitna Valley outside of Anchorage, to Nome, but the snow-short trail was so rough several mushers were injured and the survivors complained mightily.

To the north of Anchorage, snow conditions look better this year than last, but they’re not great. And in Anchorage, well, it looked to be another rubber boot weekend.

 

 

 

 

 

 

 

 

 

 

 

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6 replies »

  1. We seem to get the same amount of precipitation but less frequent cold air high pressure systems to mix with the moisture laden ocean air.

    Like

  2. The new norm seem to me to be the same as the old norm, panic sells.

    Climate changes and weather changes. We live in and exceptional area where both climate and weather change frequently. We also live in and exceptionally large state with and exceptionally small population where localized events carry undue weight due to the fact we live in a huge state with such a small population.

    When the sun stops rising in the east and setting in the west I will worry, rivers might stop flowing and snow might stop falling, that happens from time to time.

    Like

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