Avalanche Forecast
Regions: Howson, Kitimat, Nass, Northwest Coastal, Rupert, Seven Sisters, Shames, Stewart.
Use extra caution at treeline and below where persistent weak layers have been most reactive. Be aware that wind slabs could step down to deeper layers.
Confidence
Moderate
Avalanche Summary
Over the past few days several avalanches have been triggered at treeline and below on the layer of facets formed during the recent period of arctic air. Triggers have included vehicle remotes, skier remotes, naturals and explosives. These avalanches have generally ranged in size from 1 to 2.
Snowpack Summary
Wind slab could be found at all elevations. wind slabs could be found on all aspects in the alpine and treeline, below treeline cross loading will likely be found in all coastal inlets due to outflow. A new crust exists on or near the surface below 1000m.
30 to 60cm of recent storm snow overlies a variety of surfaces formed during the previous cold snap. In the alpine these surfaces are generally facets, old wind slab and Surface hoar. At treeline it is more likely to find surface hoar at this interface in sheltered terrain.
A layer of surface hoar and facets from early December can be found down 50cm in shallower snowpacks and over 80cm in deeper areas. recently this layer has not been reactive but still produces sudden results in snowpack tests.
The mid November crust is buried down over a meter in most places and is unreactive. The mid and lower snowpack is generally well settled.
Weather Summary
Friday Night
Cloudy with the possibility of light flurries bringing trace amounts of new snow. Light variable winds in the alpine and moderate outflow at valley bottom. Low of -4 at 1500m.
Saturday
A mix of sun and cloud with light flurries bringing trace amounts of new snow. Light southwest winds and a high of -4 at 1500m.
Sunday
Cloudy with up to 5cm of new snow expected for more coastal part of region. Moderate to strong south winds and a high of -2 at 1500m.
Monday
Cloudy with up to 5cm of new snow. Moderate to strong south winds and a high of -3 at 1500m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Use ridges or ribs to avoid areas of wind loaded snow.
Avalanche Problems
Persistent Slabs
There are 2 persistent weak layers in the top meter of the snowpack. The first is a layer of facets formed during the period of arctic air and buried on December 22nd. This Surface hoar could also be found at this interface in sheltered treeline features. This layer is most concerning at treeline and below.
The second is a layer of facets and surface hoar from early December. This layer could be buried as deep as 1 meter.
Both these layers are most concerning in sheltered treeline features where surface hoar is more likely to be present.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2
Wind Slabs
winds have been variable over the past few days. wind slab could be found on all aspects and elevations. Below treeline cross loading will likely be found due to outflow winds.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2