Avalanche
- Slab Width
- 76 m
- Weak Layer
- Facets
- Trigger Type
- Skier
- Vertical Fall
- 213 m
- Avalanche Type
- Hard Slab
- Slab Thickness
- 137 cm
- Trigger Detail
- Cornice Triggered
- Start Zone Aspect
- Northeast
- Avalanche Problem
- Persistent Weak Layer
- Start Zone Elevation
- 3078 m
We were walking down the ridge just E of Flagstaff face. As we moved across we remotely triggered a small new snow cornice that broke off and triggered this sizable avalanche. The avalanche started to slide on the rain crust but then stepped down to the Oct/Nov facets just above the ground.
The crown was about 4ft deep on average and approx 6ft deep at the highest, most wind-loaded point near the ridge. The slide broke about 250ft wide and ran full length ~700ft. We noted small trees braking and flagged a few old growth trees lower down in the path.
The bed surface was about 6in of very dry facets with a stout 12in pencil-thick crust sitting on top. I think this next system could overload our snowpack, especially in deep, sheltered, wind-drifted areas like this one.
We did not enter the slope to run a beacon due to hang-fire but are very confident there was no one in the drainage bellow.