Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Persistent slab activity will continue on Tuesday, with the recent snow straining the upper snowpack. Snoqualmie Pass picked up 6-11" of snow in the past 24 hours, depending on elevation. All this new snow is stacked on top of the well-documented and recently reactive 2/13 and 2/7 interfaces. Activity on these weak layers was minimal on Monday, but that doesn’t mean the problem has disappeared or that we’re in the clear. These layers may simply be more difficult to trigger right now. Regardless, buried weak layers are still present in the snowpack and deserve careful consideration.
Long shooting cracks, audible collapsing underfoot, and recent avalanche activity are all good indicators of an unstable snowpack. If triggered, these avalanches could break multiple feet deep and be large enough to bury/kill you. This setup is tricky, and you're better off not testing your luck. Avoid traveling on large, steep slopes, especially in areas of recent wind loading.
(2/21/2026)
An unintentionally triggered, widely propagating avalanche from 2/21. N, 5500ft. Its unconfirmed, but this slide may have failed on older persistent grains.
Photo: NWAC