Avalanche Forecast
Regions: Boundary, East Stikine, Howson, Kispiox, Kitimat, Nass, Ningunsaw, Northwest Coastal, Northwest Inland, Rupert, Seven Sisters, Shames, Stewart, West Stikine.
Stick to low-angle, low-consequence terrain and avoid big overhead slopes. Large avalanches continue to be remotely triggered and are propagating widely.
Confidence
Moderate
Avalanche Summary
Numerous large and very large natural and human-triggered avalanches have occurred across the region over the last few days. These include several very large (size 3) remotely triggered slabs.
Remote triggers indicate a sensitive snowpack and the need for very conservative terrain choices.
Recent avalanches have occurred on all aspects and at various elevations, on buried weak layers up to 100 cm deep.
Click on the photos below for more details.
Snowpack Summary
Strong winds from various directions have blown 40 to 70 cm of snow that has accumulated over the week. This has created thick and reactive wind slabs at treeline and above.
This snow overlies facets and a crust in many areas, and in isolated areas, buried surface hoar. Soft snow can still be found in lower-elevation terrain that is sheltered from the wind.
A thick crust with weak facets on top is buried 50 to 100 cm deep. This layer has been problematic, producing very large step-down avalanches.
The recent snow is not bonding well to these underlying weak layers, producing ongoing avalanche reactivity including remote triggering.
Weather Summary
Friday Night
Cloudy, with 0 to 3 cm of snow. 20 to 30 km/h east ridgetop wind. Treeline temperature around -12 °C.
Saturday
Partly cloudy, with 0 to 1 cm of snow. 30 to 40 km/h east ridgetop wind. Treeline temperature around -11 °C.
Sunday
Mostly sunny. 20 km/h southeast ridgetop wind. Treeline temperature around -13 °C.
Monday
Mostly sunny. 20 to 30 km/h southeast ridgetop wind. Treeline temperature around -8 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Caution required around non obvious avalanche terrain like road cutbanks, cutblocks and other non obvious avalanche terrain
Avalanche Problems
Wind Slabs
Wind affected snow can be found on most aspects. Watch for the 'typical' wind loaded features near ridgelines, and unusual features like cross-loaded gullies and ribs, or wind deposited snow lower on a slope than normal.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2.5
Persistent Slabs
Two layers of significant concern exist in the upper meter of the snowpack. They have been very reactive to human and machine triggers recently and resulted in some very large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3