Avalanche Forecast
Regions: Birkenhead, Duffey, South Chilcotin, South Coast Inland, Stein, Taseko.
Many wind slabs were human triggered and even remotely triggered in recent days as slabs formed over a dangerous mix of weak grains and crust. Daytime warming could increase this reactivity.
Confidence
High
Avalanche Summary
Wind slab reactivity continues to be the focus in recent reports. In the Hurley area on Thursday, a very large (size 3) natural wind slab release was observed on a steep north aspect in the alpine. This added to numerous other skier and remote-triggered wind slabs in the region, mainly to size 1.5.
Similarly reactive conditions have been observed on a variety of aspects in the alpine and upper treeline in recent days and are expected to persist through the forecast period.
Snowpack Summary
Wind and sun have created variable surface conditions, with northeast wind heavily impacting open terrain.
15 to 30 cm of snow sits above a widespread crust. Many areas have reported a weak surface hoar layer above this crust, which could be problematic in areas where wind has formed a slab above the layer.
Snowpack depths decrease rapidly below treeline.
Weather Summary
Friday night
Clear. Southeast alpine wind 15 - 20km/h
Saturday
Increasing high cloud in the afternoon. South alpine winds 5 - 10 km/h. Treeline temperature -2 °C.
Sunday
Cloudy with isolated flurries. Southwest alpine wind 5 - 10 km/h. Treeline temperature -4 °C.
Monday
Cloudy with isolated flurries. Variable alpine winds 0-5 km/h. Treeline temperature -2 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid freshly wind loaded terrain features.
- Wind slabs may be poorly bonded to the underlying crust.
- Surface hoar distribution is highly variable. Avoid generalizing your observations.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Avalanche Problems
Wind Slabs
Suprising wind slab reactivity has been observed over the past several days with wind transported snow having formed slabs over weak grains and a hard crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Loose Wet
Daytime warming will rob cohesion from surface layers and promote wet loose avalanche conditions in steep, sun-exposed terrain, particularly in the alpine.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 1.5