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This winter season has been an especially deadly one for avalanches. There have been 33 recorded U.S. avalanche fatalities, up from the past ten-year yearly average of 27. With a couple months left in the backcountry skiing and winter climbing season, danger remains high, and the death count is near certain to continue rising. What are the factors that have made this year so deadly?
“The driving factor behind the recent cluster of avalanche fatalities has been a widespread weak layer across the western US,” Simon Trautman, National Avalanche Specialist at the National Avalanche Center, told Climbing.
An unstable snowpack is expected every year in some spots, but what makes this year unique is how widespread it is.
“The instabilities we’re seeing this season you’ll often see in certain areas in Colorado or Utah,” said Adrian Ballinger, founder and CEO of Alpenglow Expeditions. “This type of snowpack exists every season in some places, but what’s happened this year is it’s basically across the West.”
This year’s instabilities, said Ballinger, commonly exist in certain areas of Colorado or Utah, where the snowpack is shallower and colder. This season this type of snowpack, called a continental snowpack, has extended across the west to California and Washington–which usually have wetter, heavier, deeper snow.
Weather patterns create avalanche patterns, said Trautman, and this year we saw a “blocking feature” with weather. Early in the season it was dry and cold, causing the existing snow on the ground to turn “very weak and very sugary.” This block of time between early season snow and later snowfalls is the cause of such an unstable structure.
“That’s the foundation for the snowpack,” Mark Staples, Director of the Forest Service Utah Avalanche Center, told Climbing. “It’s like a house: you have a weak foundation, you’re not too confident in your house, but what we do for the winter is we keep adding floors. We keep building on top of this thing.”
To Trautman, climate change is a complex, broad topic; placing sole blame for the weather patterns on it is too reductive, he believes. Still, it is definitely a contributing factor.
“One of the most common or well-understood factors in climate change is we’re having more extreme weather,” said Ballinger. “And so an extreme long dry period is what we had in January, what led to all these weak layers in the snow. And then really big wet storms dropped lots of new snow on top of that.”
The snow has laid the foundation for a dangerous backcountry, but the environment is only one piece of the puzzle: people also have to enter avalanche terrain in order to trigger or get caught in the slides. There has been an explosion of new users in the backcountry during the last 10 years, a trend that was only exacerbated due to the pandemic. According to NBC News, backcountry ski-equipment sales—beacons, probes, avalanche shovels, and skins—rose 74 percent from 2019. The ski and ski-boot companies Blizzard and Tecnica sold out of their backcountry lines months before the 2020-2021 season began. In December, Ballinger’s company Alpenglow Expeditions had already sold out of its Level 1 AIARE avalanche education courses through March.
It’s easier to socially distance outside of ski resorts, and many resorts have reservation systems or limits on the number of day tickets. There is also probably a pent up desire for adventure, said Ballinger, as international borders remain closed and people have been travelling less. This could be motivating more people to take to the backcountry, he surmised.
The more people on a slope, the more likely it is that someone will trigger a slide, according to bothTrautman and Staples—simple probability. But, perhaps counterintuitively, it’s the more experienced skiers who have been getting in fatal avalanches this season. Ballinger thinks—but can’t say for certain—this could be linked to more users populating the slopes.
“As the new users went into the backcountry, and so many more, I think that encouraged more experienced users to push farther, maybe not just go to the easiest, safest zones they normally would, because there’s people there,” said Ballinger.
Even people’s normal safe routes may not be safe this year. Perceiving terrain as safe over the past 10 years means little now, Trautman said, because this year’s conditions are unique relative to recent years. Ballinger addressed this decision-making bias as well.
“As experienced skiers, we need to recognize the potential bias that not getting caught in an avalanche has built in us over so many times. We still have to go back to the science and the basic decision making of what makes an avalanche slope, and on considerable and high avalanche days, we just need to not be in those places,” said Ballinger.
Due to the dangerous snowpack, Ballinger’s head guides at Alpenglow Expeditions have periodically closed off sections of their normal ski terrain in the Lake Tahoe area. Staples and others who work at the Utah Avalanche Center have responded by scaling back everything they would normally do. Some years the snowpack is like bomber granite, but this year is not that year, and so his bigger objectives will have to wait.
“The hard part is to play that long game,” said Staples. “Like, you know what, I don’t need to ski that certain peak or that certain run this year, but it’s all gonna line up. Maybe next year, maybe the year after that, but I’ll be here. I’ll be waiting.”
The snowpack may remain hazardous for the rest of this year, said Staples. It could improve, but it will likely be unstable in the immediate future. Moving forward, we should focus on what we know: the snowpack is dangerous. The deaths this year highlight the challenges we face as humans, said Staples, and adapting what we do. To Staples, this is the bigger issue, and learning from this tragic year is critical.
“Under our current scenario, we need to second guess our decisions in the backcountry,” said Trautman. “We need to get into our heads and make sure we’re taking the risks we want to take.”