Avalanche Forecast
Regions: Howson, Kitimat, Microwave-Sinclair, Nass, Rupert, Seven Sisters, Shames.
Seek out sheltered, low-angle terrain while the recent storm snow settles.
Human-triggered avalanches are likely, with deep instabilities that have produced large avalanches recently.
Confidence
Moderate
Avalanche Summary
Friday, avalanches up to 200 m wide on steep, shady slopes were reported in the Shames backcountry. Get more details here. Several size 2 wind slab avalanches on east and southeast slopes in the alpine were also reported throughout the region.
Thursday, a natural avalanche cycle up to size 3 occurred.
Natural avalanche activity will taper but human-triggered avalanches are likely through the weekend.
Snowpack Summary
Earlier this week, the storm dropped 30 to 80 cm of snow across the region. At upper elevations, the surface is wind-affected. Reports suggest soft surface snow, with sluffing, on sheltered slopes and at lower elevations.
Expect to find deeper deposits of reactive wind slab on east and northeast slopes. Changing winds may start to load south-facing slopes throughout the weekend. The recent storm snow tapers dramatically with elevation, where 5 to 10 cm sits above a firm melt-freeze crust.
50 to 100 cm deep a layer of surface hoar, facets, or a thin crust exists.
A persistent weak layer of surface hoar and facets overlying a crust is buried 120 to 200 cm deep.
Weather Summary
Saturday Night
Clear. 30 to 40 km/h north ridgetop wind. Treeline temperature -12 °C.
Sunday
Mostly clear. 10 to 20 km/h northeast ridgetop wind. Treeline temperature -8 °C. An above-freezing layer in the alpine.
Monday
Few clouds. 20 to 40 km/h west ridgetop wind. Treeline temperature -5.
Tuesday
Cloudy with trace snow. 30 to 40 km/h northwest ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.
- Recent wind has varied in direction, so watch for wind slabs on all aspects.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
Watch for newly formed and reactive wind slabs. Potential remains for slabs to step down to deeper persistent weak layers.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5
Persistent Slabs
A widespread crust with weak facets overtop is buried 120-200 cm deep. While this layer exists on all aspects, it's most likely to be triggered by a heavy load on wind-loaded slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5