Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2
In the past month, a thick layer of weak snow has been incrementally loaded across our entire Forecast Area. With each major loading event we've observed widespread avalanche activity and a pattern of human-triggered avalanches that extends for many days after loading.
On Saturday, near Galena Summit, skiers remotely triggered a 1.5-2' deep avalanche from low angle terrain (photo below/right, more details). I visited the site of this avalanche the next day (video here) and found a very similar snowpack to that found in the rest of this zone. On Sunday, in the Pole Creek drainage, a group of riders remotely triggered an avalanche that buried the road they were riding on. This happened after the 4th rider had passed underneath the starting zone above. Both of these avalanches paint a good picture of the type of conditions that exist in the backcountry right now.
Conditions remain dangerous today, it's likely you could trigger a large avalanche on most steep slopes. The best—and often only—way to manage a persistent slab problem is by sticking to lower-angled terrain. Given the possibility of remote-triggering, you'll also want to avoid being below steep slopes.
(1/16/2021) Avalanche on Galena Summit that was triggered remotely from 250' away on Saturday. The avalanche broke 1.5-2' deep in middle elevation terrain.