Quick report
- Slope Angle
- 39°
Avalanche
- Slab Width
- 91 m
- Weak Layer
- New Snow/Old Snow Interface
- Trigger Type
- Skier
- Vertical Fall
- 30 m
- Avalanche Type
- Soft Slab
- Slab Thickness
- 30 cm
- Trigger Detail
- Intentionally Triggered
- Start Zone Aspect
- North
- Avalanche Problem
- Wind Slab
- Start Zone Elevation
- 2926 m
I triggered this small D2 avalanche on the steep wind-loaded, north-facing ridge between Brighton Hill proper and 10'420. South to southeast winds were howling by mid day creating sensitive new cornices and windslabs on NW-N-NE slopes. This little test slope was easily spottable from the side and accessible from the top. As I approached the cornice, it failed triggering the slab below which propagated surprisingly 300' wide with some speed and energy. The slope was small so it ended only 100' below in the lower angle treed slope but piled up quite deep. The slope angle directly below the cornice was steep at 39-40 deg. for a short distance. I think it needed this pitch as lower angle slopes were less sensitive and more stubborn. The weak layer was a density inversion at the old snow interface about 30-40cm down. I didnt do any tests in the hangfire as most all of the slope had avalanched but Gagne has a pertinent observation on a nearby slope that highlights this same weakness.
Touchy.
View of the cornice before the avalanche from a great side bench allowed us to evaluate the size and depth of the cornice prior to exposure. Skiing was punchy but creamy and the upside-down nature of the storm slab made for challenging trailbreaking.