Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Unlikely
- Größe
- 1.5–2.5
You're mostly likely to trigger a dense, 2-4 foot thick slab avalanche on slopes facing the northern half of the compass, where the wind frequently blows, and the snowpack depth is variable. Although large avalanches are unlikely, eliminating the chance of triggering a big slide is tricky. Some visual clues to identify suspect slopes:
- Cornices, wind-pillows, and textured surfaces indicate the wind has been at work.
- If you see rocks sticking out of the snow, expect variable snowpack depths. Avalanches are easier to trigger in thin spots at the edges of slabs, near ridgelines, and along rocky, mid-slope ribs.
Remotely triggering an avalanche from flat terrain near steep slopes remains a possibility. If you do trigger an avalanche, you probably won't observe obvious signs of instability like snowpack collapsing or cracking beforehand. You can read the Forecast Discussion below for some tips on managing lingering Persistent Slab avalanche problems.
Additional discussion: Strong winds in recent days formed fresh, thin wind slabs, mostly in upper elevation terrain and predominantly on the southern half of the compass. Watch for obviously wind-loaded features near ridgelines and on the sides of cross-loaded gullies. Shooting cracks are a clear sign you've found wind-transported snow. On very steep, sun-drenched, southerly slopes protected from the wind, small loose snow avalanches are possible and could release on their own. Pay attention to the terrain above you.
(1/11/2025) We observed this recent wind slab avalanche above Dollarhide Summit in an obviously cross-loaded gully. We estimate that it failed on January 8/9 during peak winds. There may also be evidence of a refilled, deeper persistent slab avalanche along the ridgeline.
Photo: Sawtooth Avalanche Center