Avalanche Forecast
Regions: Boundary, East Stikine, Howson, Kispiox, Kitimat, Nass, Ningunsaw, Northwest Coastal, Northwest Inland, Rupert, Seven Sisters, Shames, Stewart, West Stikine.
While the SPAW may be approaching an end, this does not mean the dangerous avalanche conditions are over. Large avalanches continue to be remotely triggered and are propagating widely.
Confidence
High
Avalanche Summary
Numerous large and very large natural, explosive, 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 have created widespread wind effect and built reactive wind slabs at treeline and above. Wind direction has varied so you can expect these slabs on all aspects. In sheltered areas, new surface hoar is growing.
Several persistent weak layers are buried between 50 to 120 cm deep. These weak layers include hard crusts, weak facets and surface hoar.
The recent storm snow is not bonding well to these underlying persistent weak layers. These layers have been producing ongoing avalanche reactivity, including remote triggering and very large step-down avalanches.
Weather Summary
Sunday Night
Clear skies. Northeast ridgetop wind, 15 to 25 km/h. Treeline temperature -22 °C.
Monday
Sunny. North ridgetop wind, 5 to 15 km/h. Treeline temperature -18 °C.
Tuesday
Sunny with increasing cloud. West ridgetop wind, 10 to 20 km/h. Temperature inversion with treeline temperature -15 °C.
Wednesday
Cloudy with 2 to 5 cm new snow. Southwest ridgetop wind, 25 to 50 km/h. Temperature inversion with treeline temperature -15 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.
- 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. There is potential for wind slabs to step down to deeper layers triggering larger avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
Persistent weak layers including crust/facet combos and buried surface hoar have been very reactive to human and machine triggers recently, resulting in some very large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3