Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Likely
- Größe
- 2–3
Triggering a large, destructive 2-4 foot thick avalanche is likely. These slides will fail on persistent weak layers (crusts, crusts and facets, or facets) in the middle or bottom of the snowpack. You're most likely to trigger one of these slides in the shallower snowpacks on the eastern side of this zone and on slopes commonly exposed to the wind.
Natural and human-triggered avalanches have been observed in this zone over the past week (Observations and Avalanches). Avalanches have occurred on most aspects, primarily in wind-loaded terrain.
Persistent Slab avalanches can release in surprising ways. You can trigger them from flat or low-angle terrain long distances away from steep slopes, and they can break far above you. They can break hundreds or thousands of feet wide and after several riders or skiers have safely crossed the slope. Before triggering an avalanche, you may not experience snowpack collapsing or other obvious signs of instability.
(3/7/2024) Large natural persistent slab avalanche in the Warm Springs drainage. SE aspect at middle elevation.