Turns out, the snowpack conditions that made the weekend avalanche possible were laid down back before Christmas, when winter was warmer and snowstorms still were tangled with rainstorms. All that was needed, then, was a human to pull the trigger these many weeks later.
That's according to Stan Bones, a U.S. Forest Service avalanche analyst who also works with the Glacier Country Avalanche Center.
On Wednesday, Bones talked about that report, detailing a story that begins not with Sunday's slide, but rather back in December, when the top layers of early season snow melted and later re-froze into an icy sheet.
Since then, he said, much snow has fallen atop that sheet, layering the snowpack like a great white wedding cake. The layers, however, do not stick to one another as well as a uniform and cohesive snowpack might, and they create a slippery horizontal fault line, of sorts, when enough pressure is applied from above.
That pressure, Bones said, came in the form of Anthony Kollmann, who was skiing alone above a popular snowmobile track.
Gogolak, Bones said, “just happened to be under the avalanche when it released.”
“Just after noon,” Bones recorded in his report, “a lone skier triggered a 1- to 4-foot-deep slab avalanche on a very steep south-facing slope commonly referred to as Fiberglass Hill.”
It is a notorious slide site, the same area where a snowmobiler was badly injured back in mid-December. The day after that accident, another snowmobiler lost his machine on the same slope.
In an interview, Bones called it “very well-established avalanche topography.”
“A skiing eyewitness watched the skier” - Kollmann - “as he triggered the slide and was subsequently swept through trees and buried near the bottom of the draw,” Bones wrote in his report.
That same witness also saw two other skiers - Gogolak and his brother-in-law - working their way up the groomed snowmobile trail below. It is a popular route for backcountry skiers hiking back into the resort boundary. They, like Kollmann, were overtaken by the avalanche.
The same skier-witness, Bones reported, “quickly responded to the site of the skier who had triggered the slide, and uncovered him.”
Kollmann, however, “subsequently died at the scene of massive trauma after having been strained in the avalanche through evergreen trees.”
Meanwhile, on the trail below, Gogolak's brother-in-law was “only partly buried and able to free himself.” Gogolak, however, “was totally buried,” Bones reported. “A tremendous search effort was initiated by volunteer skiers and snowboarders from the ski area, other backcountry skiers, snowmobilers passing by, patrolling Forest Service law enforcement officers, and by the Whitefish Mountain Ski Patrol.”
Still, Gogolak's body was not discovered until about 4:30 p.m. He, like Kollmann, was new to this particular backcountry area, friends said, and neither victim was wearing an avalanche transceiver.
Gogolak, Bones wrote, “was declared deceased at the scene from asphyxia.”
The search, however, was not yet over.
Turns out “a snowmobiler on the groomed trail east and outside the avalanche area observed two other skiers run from the avalanche and become buried as they also were walking up the groomed trail,” Bones said in his report.
The search continued for those unknown skiers until well after dark Sunday evening, but, Bones reported, “without success.”
Search dogs were brought in Monday, again “with no success.”
Similar results Tuesday and Wednesday left authorities wondering whether anyone else is, in fact, buried beneath the massive slide.
The avalanche, Bones wrote, was about 800 feet wide, 1,000 feet long, and encompassed several chutes. It is piled up far deeper than the length of a standard snow probe, “up to 20 feet deep in some places.”
A snow-pit investigation along the ridge above the fracture “indicated that the failing weak layer was the contact between the failing slab and a buried melt-freeze layer formed earlier in December,” he concluded. The slope angle, he said, approached 45 degrees in the rocky cliffs near the ridge.
Adding to the danger was a three-day warm-weather system that hit on the heels of a sustained cold front, conditions “believed to have helped contribute to the fatal human-triggered avalanche.” The warming, Bones said, “degraded the strength of the snowpack.”
It was, then, a combination of traffic and terrain, of human activity and nature's basic gravitational rules. In fact, Bones said, all three slides on Fiberglass Hill this season can be traced back to that same melt-freeze layer established in December.
As of Tuesday, the Glacier Country Avalanche Center has increased the regional avalanche risk rating to “high,” which means unstable conditions are likely, especially on steep, wind-loaded slopes.
A Monday night storm, with heavy snows and westerly winds pushing 50 mph, loaded leeward slopes with deep powder pockets, a heavy addition atop the buried weak layers.
“Because of strong winds, new snow and cooling temperatures,” the center reports, “unstable slab layers are likely on steep, wind-loaded slopes in all of the mountainous areas of northwestern Montana. Both natural and human-triggered avalanches are likely. Travel in avalanche terrain should be avoided.”
Alarming as it may seem, it is not an unusual advisory for mid-January in northwestern Montana, and this season's snowpack is not any more dangerous than any other average year, Bones said.
The biggest change is not the snow, he said, but the number of people playing in it - “a lot of human triggers,” he called them.
And every day that goes by without a slide, he said, lulls those triggers into a false sense of security. “Time after time after time you can ski the same slope,” he said, and then one day it will cut loose. It only takes that once.
Yet although the current high-risk avalanche conditions are nothing out of the ordinary considering the season, Bones still urged caution, no matter the risk rating. Backcountry users should take some avalanche training, he said, should equip themselves properly, know how to use that equipment and travel with experienced partners.
And, for now at least, they should think twice before heading out of bounds.
Current weather forecasts call for additional snow and wind through the weekend, and temperatures dropping into the single digits. The National Weather Service has issued a “hazardous weather outlook,” and the Glacier Country Avalanche Center warns that “backcountry travelers need to remain alert, and avoid travel in avalanche terrain until current weather conditions abate and snow conditions stabilize.”
Reporter Michael Jamison can be reached at 1-800-366-7186 or at mjamison@missoulian.com.
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Safety first
To learn more about avalanche safety, and to find an avalanche information center and educational opportunities near you, visit the U.S. Forest Service's National Avalanche Center at www.avalanche.org.
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