Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2.5
Slab avalanches breaking on buried weak layers will be easy to trigger and can run naturally under intense snowfall and severe windloading. The north side of the compass has fragile, weak layers buried in the upper and lower snowpack (see video) and is most likely to produce remote triggers from flat terrain, widely propagating or destructive avalanches, and natural activity. Southerly aspects have a more springlike snowpack structure which will reduce chances for avalanches breaking deeper and larger than the storm snow. Manage today's persistent slab problem with conservative terrain choices.
A large natural avalanche on Schuylkill Ridge that ran during our last storm. Expect many avalanches like this today, with slabs and debris piles growing larger through the day and overnight. (2/12/2026) Photo: Miles Morris