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The Risky Business of Avalanche Problems

Social media has been alive and bristling with opinions on last weekend’s avalanche cycle. Rather than join that fray, on social media anyway, I thought I would share a few thoughts here from the perspective of an avalanche forecaster, former guide, and rescuer. Friday night, March 31, we received 12 inches of snow on light easterly winds above treeline. This snow created an unusual avalanche problem for us around here that differed greatly from the more typical wind slab problem we deal with so much of the time.  The storm slab avalanche problem present on April 1 set the stage for a number of close calls and for a number of different reasons.

I use the term avalanche “problem” in its technical sense as defined by snow scientists and forecasters around the country, and at this point around the avalanche forecasting world. In a pivotal 2004 paper  Roger Atkins, a veteran forecaster for a Canadian heliski operation, identified and defined a dozen  or so different avalanche problems as a way to clarify and provide guidance to those managing risk in avalanche terrain. Around the same time, American forecasters were revising the avalanche danger scale while also tackling the important work of addressing the nature of avalanche types in terms of size, distribution, and likelihood of triggering. Travel advice which each danger rating should include was also updated.

This process of defining properties of avalanches points to some critical concepts. The character of each avalanche type, as well as its size and distribution, directly affects your choice of terrain and how you manage it. If it doesn’t affect your terrain choice and management, it should, because certain avalanche problems can be assessed and mitigated while others may be more a roll of the dice. For example, a moderate rating on a slope with a dry loose problem presents a very different hazard than a deep but low rated persistent slab problem. I may ski the edges of a slope when a loose dry problem is present, with a plan to occasionally pull out and let my sluff pass me. Alternately, a big slope with a persistent slab problem may have me thinking about staying in the center of the slope, on the thickest part of the slab, in order to increase my odds of avoiding a thin spot which is the most probable trigger point. Both avalanche types can kill me, and each has a dynamic management strategy.

The avalanche problems last weekend required a much different risk management strategy than our more typical stubborn wind slab. A storm slab, which consists of barely cohesive slab with poor bonding to the layer below, can create ideal skiing opportunities in the right terrain. The critical detail in the last sentence is “in the right terrain”. One thing most folks with some advanced avalanche education, training, or experience could tell you is that 12” of new snow of an upside down nature on a 35+ degree slope presents an avalanche mitigation problem. Depending on your level of experience and risk tolerance, you could take a ski patroller or guide’s approach and ski cut a slope to release the avalanche. In a storm slab or loose avalanche problem this is reasonable, with a few caveats:

  • You are an expert and have done this before.
  • You have a bailout plan and an island of safety at the end of your ski cut.
  • You are confident that you can self-arrest on the bed surface if you fall down.
  • You are confident that the nature of the avalanche problem is such that the slope will crack at your feet or below, AND NOT ABOVE YOU.
  • If you are 100% confident in your assessment, step back and reflect on the nature of the universe and your role in it. If you have some uncertainty, that’s good. The resulting humility may keep you alive longer.
  • You are using safe travel practices including no one below you on the slope, skiing one at a time, and pitching the slope out in such a way that partners have eyes on the skier as well as the runout.

Two folks skinning up Hillman’s. They moved straight up into the hangfire of the looker’s left fork just before dropping into and triggering Duchess. Note that the right fork had slid earlier that morning which created the crown/stauchwall that you can see in the picture above the skiers.

Last weekend, it was fairly clear in most cases that folks were not applying many of the above concepts. The person that triggered Right Gully was alone though oddly criticized for going back up the slope to search for his pole lost while he was carried downslope. At that point, the slope was drained making the bed surface there one of the safest places to be. The party that triggered the Duchess placed no ski cut at all and made two turns center of slope in the drop in before the slope released. That was after center-punching up Hillman’s directly into fresh hangfire. The party that triggered Lobster Claw was together on the slope near the top and may or may not have understood how ugly and potentially unsurvivable the terrain trap is at the bottom. These are all big travel or terrain choice risks that can be mitigated or avoided. An experienced party triggered upper right Hillman’s from the top and with a somewhat formulated plan reduce the consequences of triggering but were admittedly surprised at the results of their ski cut. Yet another party in Gulf of Slides ski cut and triggered two avalanches, which they expected. It is likely that these groups were driven partly by the classic Scarcity heuristic. It is really hard to say no to 12” of powder. Really hard.

Our terrain is in itself a red flag due to its steepness. Thirty-five plus degree slopes present a lot of challenges to mitigating avalanche dangers and reducing exposure to risk when travelling as a small group. Rollovers obscure the view of the slope and skier below, few islands of safety exist in or near start zones, and choke points in gullies force a climber into the avalanche path. These are not insurmountable problems though they do require careful planning and discussion when figuring out a plan of attack. Group size and ability, weather, and avalanche size and character should dictate this plan of attack.

An avalanche forecast provides information about the size and character of an avalanche by identifying the avalanche problem whenever possible and when our confidence level in our assessment is high. It is critical to consider the avalanche character or problem as one of the most important factors when choosing where and when to travel. Equally important is to consider the cautionary remarks of veteran avalanche professional Don Sharaf, who recently studied the things that kill avalanche pros. “Don’t cheat the avalanche problem,” was one of the points he made to the audience at the 2016 ISSW. In other words, plans based on assumptions of the avalanche character can go completely sideways if your assumption is wrong. You can only get lucky a finite number of times before a mistake leads to disaster.

It’s probably useful to understand that my perspective on last week’s cycle is shaped by a relatively high personal risk tolerance which I likely share with everyone out skiing that day. I rock climb, sometimes soloing low fifth class terrain, and go skiing when red flags and signs of instability are apparent. Like some that day, I use terrain to my advantage on elevated danger days. But I always, and I mean always, wear a beacon, and often an airbag pack, carry rescue gear, and never travel alone in avalanche terrain when unstable snow is an issue. The Friday evening prior to this snowfall, while looking at low wind speeds and copious snowfall, I was actively engaged in a battle with my skiing desire. My emotions and desire tried to convince me that a 40 degree slope would be a reasonable target in the morning. In the end, reason won out over my emotions and I realized that low angle slopes would be the more appropriate and safer option. Indeed, I got a nice lap in that afternoon on the low angled slope next to the runout of Lobster Claw. Not a GoPro worthy hero run, but pretty darned fun.

For obvious reasons, I have a much lower risk tolerance when at work or when making decisions for others in elevated risk environments. I also understand and frequently remind myself that being wrong about the nature of the avalanche problem only needs to happen once, and being wrong once can kill me or a friend. I had the misfortunate of being caught and carried when what I thought would be a manageable sluff turned into a wet slab that broke upslope behind me. In that case, I only received minor injuries and a broken ski several miles into the backcountry but the subsequent reflection on the experience made for a great learning opportunity.  I’ve been involved in enough other avalanche incidents to understand that skiing and climbing are very dangerous games. Part of my strategy to remain alive and kicking is to be honest with myself when reflecting on risks. Whether I was right or whether I was just lucky is the question I ask myself at the end of every day I’m out in the field, now more than ever.

-FC