Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Likely
- Tamaño
- 2–2.5
Recent Avalanches: It has now been 5 days since the natural avalanche cycle that followed the Thanksgiving storm. Very widely propagating natural avalanches occurred on Seattle Ridge. On Friday last week there was a human-triggered avalanche on Sunburst and remote-triggered avalanches in the Tincan Trees. Several new glide avalanches were reported yesterday in both Turnagain Pass and Summit Lake.
There are three layers of buried surface hoar throughout our zones with the upper most layer about 2' below the surface in Turnagain Pass. These layers exist through treeline and up to the ridgetops on all aspects, although it is less likely to trigger them where a crust exists. This problem is so tricky because natural avalanches are unlikely, but the chance of a person triggering one of these large avalanches is uncertain and the consequences could be devastating, especially if there are rocks, trees, or gullies below the slope.
Buried surface hoar is notorious for giving either no information or bad information. When the situation is so hard to assess, we always come back to travel advice to guide us in our danger rating choice and right now sticking to low angle slopes is the best option for a safe day.
(11/28/2025)
Crown of an avalanche in Jr's. on Seattle Ridge that was most likely triggered on the Thanksgiving buried surface hoar. This avalanche was almost 1 week ago, but that layer is everywhere and not to be trusted.