What's Your Problem?

Written by: Brian Lazar, CAIC Deputy Director & Central Mountains Regional Manager

We can predict the type of avalanche more confidently than our exact chance of triggering one. This idea underpins the "Avalanche Problem" concept, which outlines nine avalanche problem types used in North American public forecasts.

Roger Atkins, a long-time heliski guide, first proposed this concept in 2004, and it has since been adapted for public safety messaging needs. This framework helps us understand that managing avalanche terrain is as much about the kind of avalanche expected as it is about the overall danger rating or snowpack stability. 

Understanding these problem types is crucial for personal risk management in the backcountry. With practice, they become as vital as the danger rating when planning trips, as they define different kinds of “avalanche regimes that require different risk management strategies” (Atkins, 2004).

These nine problem types can be grouped into four broader categories: persistent weak layers, storm snow, wet snow, and cornice/glide avalanches.

The nine types of avalanche problems you will find in a forecast. Some forecasts may have more than one problem listed. In addition to type, a forecast includes location, likelihood, and size of potential avalanches.

Persistent slab avalanche

Storm Snow Instabilities

This category includes Wind Slab, Storm Slab, and Dry Loose avalanches. They break on non-persistent weak layers and typically pose a threat for only a few days, though Dry Loose avalanches in old, weak snow can last for a while during prolonged dry spells. Storm snow instabilities are more predictable, confined to traditional start zones, and not triggered from a distance, making them easier to manage.

Risk Treatment: Wait a day or two for instabilities to stabilize before entering steeper terrain. Avoid suspect slopes identified in the forecast.

Wind slab avalanche

Wet Snow

Wet snow avalanches manifest as Wet Loose or Wet Slab avalanches. Both kinds of avalanches require liquid water in the snowpack. Wet Loose avalanches are more common and predictable. Wet slabs are harder to predict since they require water reaching a buried weak layer or concern, but occur during prolonged warming or rain-on-snow events.

Risk Treatment: Travel earlier in the day when temperatures are colder. For Wet Slab concerns, avoid identified terrain and use wider buffers due to uncertainty.

Wet loose avalanche

Cornice Fall and Glide Avalanches

These are two very different kinds of avalanches, but they are both exceedingly difficult to predict.

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Glide avalanches are the release of the entire snow cover as a result of gliding over the ground.

Forecasters identify favorable conditions, such as rapid cornice development from wind drifting, warm-ups causing cornices to sag, and liquid water pooling at the ground.

Risk Treatment: Avoid traveling under cornices and slopes with glide cracks (full-depth cracks that are visible across the slope) or those warned about in the forecast.

Glide avalanche

When planning trips, don't solely rely on the danger rating, which can tell you the likelihood of triggering and the potential size. The kind of avalanche you expect offers critical information on how to navigate the terrain.

Always ask yourself and your partners, "What's your problem?"