Avalanche Forecast
Regions: Boundary, East Stikine, Howson, Kitimat, Nass, Ningunsaw, Northwest Coastal, Rupert, Seven Sisters, Shames, Stewart, West Stikine.
Slab avalanches have been reactive to human triggers and even remote triggering from afar. This is most likely where the snow is wind affected and sitting above buried surface hoar or a crust.
Confidence
Moderate
Avalanche Summary
On Wednesday, the pattern of human and remotely triggered avalanches continued. Most recent avalanches have been up to size 1.5 with a few larger ones up to size 2.5 reported on Monday. These avalanches have been occurring at treeline and above and on all aspects. Almost all of them have failed on the layer of surface hoar or crust described in the snowpack summary.
Snowpack Summary
Exposed terrain at treeline and above is highly wind affected. In sheltered terrain a new layer of surface hoar is forming on the surface and a new crust may be found on steep south facing slopes.
Another layer of surface hoar and facets is buried 10 to 30 cm in sheltered terrain.
Below treeline a thick melt-freeze crust exists down 20 cm and up to 1700 m.
Weather Summary
Thursday Night
Clear skies. 20 to 30 km/h east alpine wind. Treeline temperature -5°C. Freezing level valley bottom.
Friday
Sunny. 15 to 25 km/h southeast alpine wind. Treeline temperature -5°C. Weak temperature inversion. Freezing levels 600 m.
Saturday
Sunny with cloudy periods. 10 to 20 km/h southeast alpine wind. Treeline temperature -6°C. Alpine temperature inversion -1°C. Freezing levels 500 m.
Sunday
A mix of sun and cloud and isolated flurries. 15 to 20 km/h southeast alpine wind. Treeline temperature 0°C. Freezing levels 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Be carefull around freshly wind loaded features.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Avalanche Problems
Persistent Slabs
A layer of surface hoar and facets in the upper snowpack will likely remain rider triggerable. This layer is most problematic in sheltered terrain at treeline.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Wind Slabs
Over the past few days wind has come from a variety of directions at all elevations. Wind slab is possible on all exposed slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5