Avalanche Triangle – How to Sort Information

The avalanche triangle is one way to sort information in the world of snow and avalanches. We can sort information using TERRAIN, SNOWPACK, WEATHER, and the HUMAN FACTOR.

When thinking of terrain, we ask “Is the Terrain Steep Enough to Avalanche?” The majority of slab avalanches occur in terrain that is 30° – 45°.

When thinking of snowpack, we ask “Is There a Recipe for an Avalanche? Is there a SLAB, WEAK LAYER, BED SURFACE and are we in TERRAIN steep enough to avalanche?”

When thinking of weather, we ask “Is the Weather Contributing to the Instability?”

And when thinking of the human factor, we ask “Is my Group Working as a Team?”

North American Danger Scale – Danger Ratings and Avalanche Forecasts

Each avalanche forecast offers a tremendous amount of information.  Most forecast centers offer daily danger ratings.  The danger scale goes from Low to Extreme, and offers a danger rating, commentary on the likelihood of triggering an avalanche, the size and distribution of avalanches, and travel advice.  

Here’s a great blog post from the Utah Avalanche Center about interpreting the danger rating.

Route Planning Foundations

Route planning starts long before you head out on a tour. Here are a few tips as you begin route planning.

The Conceptual Model of Avalanche Hazard, Avalanche Problems and Making Decisions

A lot of information goes into making a decision in the backcountry. Before you head out in the morning, take the time to gather data – what has the weather been doing in the last 24 hours? Has it snowed? Has the wind been blowing? What avalanche problems will likely be present on your tour? Build a hypothesis of conditions and then check the avalanche forecast. What do the experts say?

Understanding the forecasted avalanche hazard and avalanche problems before leaving on your tour can help you and your team make better decisions. Here’s Jenna Malone’s explanation about why having a systematic approach is important.

Many aspects of the Conceptual Model of Avalanche Hazard are referenced in the AAI Backcountry checklist. This is a great tool for sorting and prioritizing information in the field.

Here’s an article about the Conceptual Model of Avalanche Hazard.

And here’s the blog from the UAC that she referenced, written by Drew Hardesty.

What Do Traveling in Avalanche Terrain and Playing Poker Have in Common?

Backcountry skiing and poker have a lot in common. In both, there is a lot of hidden, unknown information and a whole lot of uncertainty. Learning how to sort and prioritize information and make decisions in a high-uncertainty environment is important to backcountry travel, as well as poker playing.

How can you tell if you made a good decision or just got lucky? How do you evaluate the quality of your decisions?

These are a few things that Jenna Malone will discuss in the following video.

Want more? Here’s a link to Thinking in Bets by Annie Duke, that Jenna is referring to.

A Deeper Dive into Group Dynamics, Decision-Making Influences and The Human Factor

There are many factors that can influence decisions. Sometimes, when traveling in the backcountry, a group uses a checklist, clearly communicates, and comes to a decision in a consensus manner, choosing to ski a slope based on their observations and the forecast. Other times, there is little communication, and a group might follow one person, the leader, on whatever tour they have chosen for the day. And still other times, there might be no clear leadership on a day of touring.

We want to spend some time discussing a variety of factors that might influence our decisions in the field. We spend time studying how humans interact as a group and what might influence communication and decisions, as poor communication or lack of communication is a factor in many avalanche accidents.

The following video series presented by Jenna Malone will discuss the Human Factors and Decision-Making. In addition to being an AAI instructor, Jenna is a PA, a ski patroller, and a guide. She is able to offer a broad perspective on decision making and how the human factors influence these decisions.

Here’s the original research article about Heuristics from Ian McCammon.

Want even more? Here’s the paper that covers Strategic Mindset. This piece is often used in guide service operations.

West Couloir Accident Review

Do you have your red flags written down?

Now that you have spent time reviewing the accident, as well as the snow and weather conditions in the days leading up to and the day of the accident, let’s review what stood out to Jake.

West Couloir, Kessler Peak

In this video, Jake Hutchinson introduces the accident that we are going to review. This accident occurred in the West Couloir on Kessler Peak in the Wasatch.

The goal of reviewing this accident is to learn from it. It is not to criticize those involved as individuals. The more we know about avalanches and avalanche accidents, the more we can hope to recognize similar situations and choose alternative routes or alternative solutions.

If, for any reason, this accident review is triggering for you, please skip this exercise and move on to the other material. It is not required that you participate in this accident review.

Take notes on the obvious clues within terrain, snowpack, weather, and human factors that may have had an impact on this incident. Have these notes handy at the pre-course Zoom Meeting. We will spend some time at that meeting discussing/debriefing this incident.


Here is an article about the accident. And a second article can be found here.

The Accident Report from the Utah Avalanche Center can be found here.

And the accident site can be found here. If the accident site doesn’t pull up immediately, use the search bar and search “West Couloir fatality”