Sawtooth & Western Smoky Mtns

Triggering a large avalanche that breaks widely is your main concern today. While the likelihood of this is gradually decreasing, it is still a worrisome possibility. Don't expect any signs of instability before triggering an unsurvivable slide. These avalanches can be triggered from long distances away and run into terrain far below. 

Yesterday, a group of skiers remotely triggered a very large avalanche on Saviers Peak. Without receiving any signs of instability, the slide broke 100' below skiers on the ridge above. This slide broke on persistent weak layers 1-2ft down in the snowpack, ran to valley bottom over 1000' below. Two days ago, a group of skiers in the Baker Creek drainage triggered an enormous collapse that traveled over 1,500 feet, shattering the snowpack across a broad area. The skiers were on their third lap up their skin track when they felt the slope collapse and watched fractures spider-web the snow in front of them. On a steeper slope, this collapse would have triggered a massive avalanche. In both cases, these were the first signs of instabilities.

Navigating MODERATE Avalanche Danger with our widespread persistent slab problem is no walk in the park. There is no golden rule, or set of rules, that will give you the red light or green light to ski a slope. We can give ourselves broad brushstrokes of terrain characteristics as aids for picking slopes that are less likely to slide and that have less severe consequences. Slopes where you are most likely to trigger these slides are going to be wind-loaded, thin, rocky, alpine terrain with steep rollovers. Terrain where you're less likely to trigger an avalanche and consequences will be lower are going to be evenly covered, with clean runouts that have no terrain traps at the bottom (trees, rocks, cliffs to be strained through). With this being said, these are not rules but trends. 

To move through the mountains is to accept uncertainty — we can never control every aspect of a day. Terrain selection is how we get to pick how much uncertainty we accept. While MODERATE Avalanche Danger means that there are many slopes of avalanche terrain you can ski and not trigger a slide, the chance of triggering a large, unsurvivable slide remains possible. As a mentor, and fellow forecaster who passed away last week, told me on my first day out in the field with him: "We study layers and grains, collect observations, and think that we know. But you can't know. And neither can I. We're always playing a game of odds." He reminded me of this throughout the season, asking me, "do you really know that" many times while still enjoying many days of great skiing in avalanche terrain.  Try to remind yourself of this as you're moving through the mountains. If you choose to enter avalanche terrain, you can use your terrain selection to stack those odds in your favor.