Avalanche center hopes Colorado can avoid repeat of deadly 2020-21 winter
12 fatalities statewide were the most since 1992-93
The Aspen Times
EAGLE — The Colorado mountains are notorious for receiving substantial snowfall in October and November, then getting a dry spell that results in a rotten base layer.
Last winter was the poster child for those conditions, and it resulted in a deadly winter for avalanches. The 12 fatalities were the most recreational avalanche deaths since 1992-93 and double the state’s 10-year average, according to a recent summary by the Colorado Avalanche Information Center in The Avalanche Review, a publication by the American Avalanche Association.
“Only pre-WWII mining days saw seasons with more avalanche fatalities,” wrote Brian Lazar, deputy director of the avalanche center.
Lazar said this winter is starting off with generally safe conditions that could change with the most recent storm.
“It’s not the same as last year,” Lazar said. “The difference is this year the early-season snow cover is much less contiguous compared to last year. It really is confined to the northerly, maybe east-facing slopes at really high elevations, so the upper stretches near treeline and then Alpine.
“At this point last year, we had snow cover much more contiguous across the landscape, which then made the weak layers much more contiguous across the landscape, so when we finally got snow, it built slabs, and we saw bigger avalanches.”
After a dry stretch to start December 2020, it started snowing Dec. 10. Across the state, there were 93 human-triggered slides the following week as powder-starved backcountry travelers were eager to finally get outdoors. It was the most human-triggered avalanches in a week in Colorado history, according to the avalanche center. As snowfall kept piling up, the slides got bigger. The first avalanche fatality occurred Dec. 18, when a skier got caught, buried and killed west of Crested Butte.
Another dry period in January created another weak layer and established conditions that resulted in more deadly slides once snowfall returned.
This winter, there were a couple of storms in the High Country in October and November, and there were also pronounced dry periods with cold nights.
“We have generally safe avalanche conditions because we just don’t have any snow,” Lazar said before the most recent snowstorm. “The good news (of) these warm, really dry conditions is that many slopes melted back to bare ground. We kind of get to start over in all those places, so that is good news for us.
“But it’s not going to be the case everywhere. The places that held onto the snow — they’re going to be the first to produce the big avalanches — are those high north, northeast maybe east-facing slopes in the Alpine.”
The prolonged dry stretch into December, he said, was a good time for backcountry travelers to take note of the slopes that held snow because they will likely develop into problem areas in the future.
“It’s just weak, sugary snow from top to bottom in places that it survived,” Lazar said.
With the snowstorm this week, backcountry travelers must realize “we’re in store for a fairly dramatic change in avalanche conditions,” Lazar said.
The Wednesday-Thursday storm system dropped as much as 11 inches on Summit County ski areas with another 2-5 expected to fall Friday.
“We want people to realize winter is here; it’s coming,” Lazar said. “… Check the forecast because things are going to change very quickly.”
A daily forecast is available at Avalanche.State.co.us. As of Friday morning, the report showed considerable avalanche danger (3 out of 5) in the Vail and Summit County zones.
“You can trigger large dangerous avalanche today,” the reported stated. “New snow and wind will overload our weak snowpack.”
In the 2020-21 winter assessment for The Avalanche Review, Lazar noted that the Colorado Avalanche Information Center tried several ways to get the word out last year about the hazardous conditions but still saw a high number of fatalities.
“We hope the historic numbers of avalanche fatalities, multiple-involvement accidents and multiple-fatality accidents are just anomalies and not the sign of a worrisome trend,” he wrote.
This story is from AspenTimes.com. Summit Daily News contributed to this report.
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