Avalanche! Life and death by degrees

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By Eric Ming, Watch Contributor

 

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The Battleship heading on a collision course with Hwy. 550.  Jonathan Thompson photo

On Jan. 5, a skier participating in an avalanche course in Senator Beck Basin on Red Mountain Pass was buried under three meters of avalanche debris and killed.

Two in-bounds skiers were caught in a slide on Kachina Peak, at Taos Ski Valley, on Jan. 17. Both were trapped under the snow for around 20 minutes and eventually died.

On Jan. 21, a skier in the Ashcroft area, near Aspen, was buried on a slope near where he had been skiing for the previous two days.

The Colorado Avalanche Information Center (CAIC) listed 193 avalanches in 10 days last month, between Jan. 19-29 — and those were just the slides that were reported.

“So far this season, CAIC has recorded 54 people caught in avalanches,” the state’s forecasters wrote on Jan. 25. “Nineteen people were partially buried (three of whom had their heads beneath the snow) and four were completely buried. Tragically, two of these accidents resulted in fatalities.”

By contrast, “On average in a single season, CAIC gets reports of 63 people caught in avalanches and six people die in avalanche accidents.”

“The numbers above are just the incidents we know about, and we’re only halfway through the season. Bottom line: We have dangerous snowpack conditions this year, and even if we inch across the line to Moderate danger, conditions will not be safe for the foreseeable future. Most avalanche accidents happen when the avalanche danger is rated MODERATE or CONSIDERABLE.”

By Feb. 1, the numbers went up again, and the CAIC documented three more people caught in avalanches. These are “impressive and scary” statistics, the forecasters wrote.

Nine out of every 10 avalanches is caused by a backcountry traveler, and this year’s cycle seems far fiercer than usual. Is it because there are more people out there than usual? Is this going to be the year that snow riders recall as extremely volatile and/or especially deadly?

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Jerry Roberts readies 50 lb. charges for helicopter mitigation.  Mark Rawstoned photo

Jerry Roberts has labored over 40 years in the San Juans forecasting weather and avalanches for various organizations including the Colorado Department of Transportation, CAIC, INSTAAR and many avalanche education programs. Based on statistics in stacks of yellow, Rite in the Rain notebooks that he kept each winter on snowpack and weather conditions, he said, “Only six years were stable as a Mormon marriage. The San Juans are a desert range, dry, with a shallow snowpack and few storms.”

Such characteristics make for what he calls a “conditionally unstable” snowpack.

“You can’t ski the San Juans aggressively. You might get away with it for awhile, based on dumb luck, but eventually you’ll get caught,” Roberts said. “Ask many of the locals who’ve been buried numerous times. Pick your posse carefully — not one filled with Type A personalities, but a group with a variety of personalities. Beware of the ‘Expert Halo’ trail boss. No one wants to be the timid one, but you should always speak up and question a decision in a group if you are uncomfortable.” Snowpacks have regional climate characteristics, and Colorado’s is known as a “Continental” snowpack. This type of snowpack tends to be shallow, with temperature gradients that create faceted, depth-hoar snow crystals — and can result in long-term, unstable layers often buried near the ground. A Continental snowpack is considered extremely capricious and unpredictable when it comes to skiing or boarding safely, and snow in the San Juans, in particular, is generally the sketchiest of the lot.

Ridgway resident Angela Hawse is the president of the American Mountain Guides Association, and a former forecaster for Telluride Helitrax. “We have the worst Continental snowpack anywhere,” Hawse said. She employs a conservative strategy in the San Juans. “Everyone has to be a forecaster,” she said. “The days of going along with the group, expecting someone else to be the leader and casually ignoring safety protocols and equipment, are no longer appropriate.”

Peter Lev is a contemporary of Roberts, having worked in Little Cottonwood Canyon, Utah, for the highway department, the Alta ski area, and as a forecaster and lead guide for Mike Wiegele’s helicopter operation in Canada.

“The Wasatch is pretty well known for lots of avalanches,” he said, “but Colorado takes the cake for its Continental snow climate. That’s why there are so many deaths here. And hazards exist frequently into spring. It doesn’t go away; it just goes into relaxed mode every so often.”

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A natural slide from mid-January crossed the Ophir Pass Road, near Red Mountain Pass. (Photo by Bill Liske)

INCREASING CROWDS,

Red Mountain Pass seems to have been discovered this year: the number of skiers appears to have increased, along with new huts and yurts that accommodate overnight skiers and those looking for guides and avalanche courses. Roberts recalled when three cars parked on the pass was a big day; now Red is going the way of Teton Pass in Wyoming and Berthoud Pass on the Front Range, with their backcountry crowds and all the complications that go with finding parking, to having groups skiing above you in hazardous places, to turning a potentially untracked paradise into a tracked up, ski-area-like wasteland.

Hawse views more people overnighting on Red as a numbers game, where there are “more people without experience, and there will be more incidents. But the culture of sharing (avalanche information) is changing in a positive way,” she added. “People’s willingness to send observations to online avalanche sites is going to prevent more accidents.”

Roberts observes that statistically, the number of “winter recreationists doubles every five years but avalanche fatality rates have remained flat for the last 20 years.”

The question is whether avalanche training will be enough, given the increasing crowds. We’ll see if that holds true.

Lev believes that the moon’s gravitational pull influences not only tides but also snowpacks — and that as a result, there is more tension in the layers of a snowpack at certain times than there is at others.

“Sometimes the snowpack’s more relaxed,” he said — and people can get by with skiing things that might not otherwise be safe.

By contrast, in conditions like we’ve had the past few weeks, he advises pulling back to “pet runs,” places that you know well and that are safe to ski.

A MATTER OF DEGREES

The slide on Jan. 21 that killed a skier south of Ashcroft happened on the third day of the trip. The group had been doing laps on a nearby slope with an angle of less than 30 degrees, according to a CAIC report. On Jan. 21, the skiers moved to a slightly steeper slope that tilted about 35 degrees. In a season with this much instability, those extra four or five degrees made all the difference, and a skier triggered a release 400-foot wide and 2-to-4-feet deep that ran 600 linear feet.

The angle of the slope that failed in Senator Beck Basin was between 32 and 34 degrees, according to the post accident assessment by the CAIC. The probability of a slope avalanching over 30 degrees goes up significantly, especially in seasons where there is buried weakness in a snowpack (and there is almost always some weakness).

The Utah Avalanche Center offers an online training program called Know Before You Go. In the section entitled “Get Out of Harm’s Way,” there is crucial information about angles and the importance of slope steepness. Statistically, most avalanches are triggered on slopes between 30 and 45 degrees. When the Ashcroft skier decided to transition from a northeast-facing slope below 30 degrees to a slope of 35 degrees, on a day where there had been an avalanche warning specific to northeast slopes, he was moving into a perfect storm.

For 25 years, Roberts taught snow science/avalanche courses to students from Prescott College.

“Avoid the hazards,” he said. “Avoid getting caught. Take the old man route back home. Good route finding will always serve you well, and is the most important skill you can develop for the winter mountains.”

Because snow and weather conditions vary, forecasters divide travel areas into zones. Colorado has 12. Lev considers avalanche forecasts “broad brush strokes.”

“We have to remember, there are hundreds of slopes out there that can behave differently,” he pointed out. As accurate as forecasts can be, there are still endless variations not only in big ski lines, but also on small slopes and terrain traps (features that can bury you just as easily). Roberts advises stepping aside from the group and making your own “environmental observations.” He calls the personal sphere that your inner snow safety specialist engages in “Nowcasting.” Use your “patroller’s legs” to feel  the snow density: is the slab collapsing/fracturing or for anything in your immediate surroundings that hints at instability. It’s all part of the package that makes for a safe day  in the mountains.

“Every year is a new experiment,” Roberts summed up. The snow depth is different, the wind is from an unexpected direction and the water content (CWE) varies from storm to storm. It is hard to standardize and make generalizations.

Hawse tells her winter clients, “This isn’t the place to ski the gnar.” They are encouraged to come back in spring if they want to ski bigger lines. She says her “Spidey sense gets up” when she is on slopes of about 33 degrees. When Hawse worked for Helitrax, and the slope had been mitigated with explosives, 35 degrees might have been OK to ski. But if the slope hasn’t had the shock of explosives, she said, she is going to ski lower angled terrain.

She also reads the full day’s forecast, and any hazards that may exist, on avalanche sites. “People don’t do a very good job of alerting properly to the yellow colored ‘Moderate’ rating on avalanche sites. They don’t even take the rating ‘Considerable’ seriously enough,” she said. Reading all the analysis is critical, she said — not just skimming the colors on the hazard tabs. You start to understand forecasting when you can put all the components together: weather, snowpack history and weaknesses, wind, slope angles and surrounding terrain.

Hawse also agrees with her mentor, Jerry Roberts, that “hasty pits” — quickly dug snowpits — are an effective way to assess conditions as you travel. They’re efficient, and can tell you a lot about how the snowpack is holding together. She keeps a probe clipped to her pack so it is readily at hand, and she can poke around in snow that she is unsure of. Although there are apps you can download on your phone that show a slope’s angle, Hawse uses a compass (an old LifeLink Slope Meter accomplishes the same thing).

All three skiers have spent decades managing avalanche risks for the safety of untold numbers of people, whether they were skiing and riding in hazardous mountain terrain or merely driving up Red Mountain Pass or Little Cottonwood Canyon. And they all have their own version of pulling back to Lev’s “pet slopes” — places with angles of 30 degrees and lower when things are unstable and risky.

“We are not done with this season — not even a chance,” Lev emphasized.

Roberts reiterated the words of the Buddha: “Kill the ego, kill the desire” when it comes to skiing or riding the big line that might kill you.

 

IF YOU GO

Before you leave the house, check out the Friends of the CAIC’s Instagram page, which has photos of recent slides (an education in and of itself).

Jerry Roberts has collated seemingly every relevant avalanche and weather related site in one place, with links to remote weather stations, road conditions, extended forecasts, jet stream, radar, infrared, SNOTEL, highway cameras and more at: therobertreport.net/weather-links-2/

State weather stations can be found here: avalanche.state.co.us/observations/weather-stations/.

The Utah Avalanche Center’s excellent online education program, ‘Know Before You Go,’ is free of charge. The videos they’ve produced offer a good sense of getting caught in a slide. Find both at utahavalanchecenter.org.

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A definition of a conditionally unstable snow pack from INSTAAR Occasional Paper
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