Cooke City has a deep slab problem: a 7+ foot thick snowpack resting on a layer of facets. This recipe might be a preview for the rest of our forecast area since there are still months of winter left. I tried to explain the problem with the analogy below. A proper, technical definition can be found on the Colorado Avalanche Information Center's website.
DEEP SLAB INSTABILITY: an analogy
Published in December issue of SnoWest Magazine
Snowmobilers die in avalanches every winter, killed by trauma or suffocation, an extremely unpleasant way to breathe your last breath. In the last 10 years 93 snowmobilers in western America have been killed in avalanches. This is no surprise. We love to ride steep, open, mountainous slopes in avalanche terrain. If you play in the lion’s den you may get eaten, but as riders we don’t have to go into the den when the lion is hungry.
Anyone who travels in the mountains when there is snow on the ground needs to know how to avoid being caught in an avalanche. This includes hunters who chase game like deer, elk, sheep and mountain goats. Read the full .pdf to learn more about avalanche avoidance.
On February 25, 2015 the Panjshir Valley in Afghanistan had an avalanche cycle that killed at least 168 people. The reports at the time claimed over 200 dead making international headlines. A few weeks ago I visited the valley and wrote this "Official" report. I wrote it for Hameed Habibi who runs the Afghanistan Avalanche Control Team at the Salang Tunnel.
The fatality numbers (168) are the best we could gather based on interviews. If anything, they might be slightly understated.
A large, 8-10’ deep avalanche on Woody Ridge outside of Cooke City yesterday (1/30) surprised me and is making me reexamine what I know – and what I don’t know – about the snowpack in the Cooke City area. I'm giving this zone a lot of thought because, depending on what the next storms do, we may be at the start of a significant avalanche cycle.
The snowpack changes from year to year, even day to day but, the terrain on which snow falls remains constant. Understanding and recognizing avalanche terrain are critical tools for safe decision making in the backcountry.
During stable snow conditions, riding in avalanche terrain is safe and acceptable. When snow conditions are unstable, avoiding steep slopes and avalanche run out zones is key to avoiding avalanches.
Presented at the 2014 ISSW in Banff, Canada.
Conducting stability tests in avalanche terrain is inherently dangerous since it exposes the observer to the potential of being caught in an avalanche. Recent work shows that such exposure may be unnecessary since the results of extended column tests (ECTs) and propagation saw tests (PSTs) are largely independent of slope angle, allowing for data collection in safer locations.
Published in Carve, March 2014
In a career of 15 years I have investigated a lot of avalanches. The most interesting ones are unintentionally triggered and are intriguing because they usually involve a series of decision-making failures only obvious in hindsight. This winter has been rich in such experiences. Folks have triggered many avalanches and a few have been caught and one died. Over President’s weekend three skiers were in an avalanche they triggered while skinning up Beehive Basin to the north of Big Sky. Small mistakes stacked up to create a potentially deadly situation. All too often my avalanche accident investigations involve a fatality. This accident ended with a rescue and only minor injuries. Although terrifying and sobering for those involved, I am excited about the possibility to learn and pass along the lessons to others. Avalanches involving buried skiers that don’t end tragically are rare and, to an avalanche educator, a gift.
