Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible - Likely
- Size
- 1–2
Recent westerly wind formed slabs above crust and surface hoar layers in alpine and treeline terrain.
Steep open slopes are the most dangerous, as wind slabs may be slow to bond.
Recent westerly wind formed slabs above crust and surface hoar layers in alpine and treeline terrain.
The early December weak layer remains a concern in areas with a shallow snowpack, particularly on steep rocky slopes.
Two notable avalanches occurred in the Dogtooth Range on Saturday:
A skier was caught in a size 2.5 wind slab avalanche that propagated widely across a northeast-facing slope. It ran on a 5 to 40 cm deep surface hoar layer. See this MIN report for details.
A group of skiers remotely triggered a size 2.5 persistent slab avalanche on a large southwest-facing alpine slope.
Many smaller (size 1 to 1.5) wind slab avalanches were also reported across the Purcells.
Surface hoar and sun crusts are developing on the surface. Recent snow (10 to 30 cm) sits on a variety of interfaces including surface hoar in sheltered areas and sun crusts on solar slopes. Deeper wind-loaded pockets also exist above these layers.
A weak layer of facets buried in early December is on average 60 to 90 cm deep (except closer to 30 cm in the shallower eastern parts of the Purcells). This layer continues to cause occasional large avalanches in the Golden and Invermere areas.
The snowpack base consists of a thick crust and facets in many areas.
Sunday Night
Partly cloudy. 20 km/h northwest ridgetop wind. Treeline temperature -12 °C.
Monday
Sunny. 10 km/h northwest ridgetop wind. Treeline temperature -6 °C.
Tuesday
Mostly sunny. 10 km/h west ridgetop wind. Treeline temperature -5 °C.
Wednesday
Mix of sun and cloud. 20 km/h west ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.