Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
The same layer of buried surface hoar that is causing large and dangerous avalanches in the Turnagain Pass and Seward forecast areas also exists in Summit Lake. However, due to the general lack of recent snowfall in the area, it seems to be much less widespread and is only a concern on wind loaded slopes or in areas that tend to get more snowfall than the majority of the Summit Lake forecast zone. We have seen a few examples of avalanches that most likely released on this layer, one small avalanche on Tenderfoot on March 3rd and another large avalanche on LV Ray near Carter Lake on March 11th.
The layer of buried surface hoar could cause wind slabs to remain triggerable by a person for much longer than normal. The size of these avalanches is expected to be much smaller than in the other forecast areas due to the lack of widespread snowfall in recent weeks. However, we still want to let folks know that this is a potential issue in Summit Lake.
To assess the conditions, you can use hand pits or snow pits to check for the weak layer within the upper 1-2' of the snowpack. Typically, if the layer of surface hoar is intact, you will have easy shears in hand pits and unstable results in snowpit tests. Since the layer stayed on the surface for longer in Summit Lake, wind, sun, and ski tracks likely destroyed it in many areas before it was buried.
(3/11/2025)
Cornce fall that triggered a large slab below in the Carter Lake area that is south of Summit Lake. This occurred on Monday, March 11.