Avalanche Forecast
Regions: Coquihalla, Harrison-Fraser, Manning, Skagit.
Very dangerous avalanche conditions continue at all elevations. Avoid all avalanche terrain.
Natural and human-triggered avalanche activity remains likely.
Confidence
Moderate
Avalanche Summary
No recent avalanches have been reported in the region however poor visibility and high avalanche danger kept many users out of the backcountry on Wednesday.
We expect those who head into the backcountry on Thursday will see evidence of a widespread natural storm slab avalanche cycle that occurred during the storm.
If you do head out please consider reporting and observations and photos from your day to the Mountain Information Network.
Snowpack Summary
Up to 70 cm of storm snow overlies wind-affected surfaces and old wind slabs in exposed areas and 30 to 60 cm of settling snow in sheltered areas.
Multiple weak layers exist in the upper and mid snowpack. The most concerning weak layer is a widespread crust found down 60 to 100 cm, with weak, faceted snow immediately above it. This layer will need time to adjust to the new snow load. Although natural avalanche activity may taper out on this layer as the snow stops falling it will remain possible to human-trigger it for some time afterward.
Weather Summary
Wednesday Night
Cloudy with 25 to 35 cm of snow. 40 to 60 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level drops to 500 m.
Thursday
Cloudy with 5 to 15 cm of snow. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing level hovers around 500 m.
Friday
Partly cloudy with 1 to 2 cm of snow. 20 to 40 km/h south ridgetop wind. Treeline temperature -6 °C. Freezing level rises to 1000 m.
Saturday
Partly cloudy with 2 to 3 cm of snow. 20 to 40 km/h southeast ridgetop wind. Treeline temperature -6 °C. Freezing level rises to 1000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Avalanche Problems
Storm Slabs
Storm snow and strong winds have built touchy slabs at higher elevations. Deeper deposits are expected in north and east facing terrain around ridgelines. Investigate how the new snow is bonding to the underlying crust as you travel.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2.5
Persistent Slabs
A problematic combination of weak faceted snow and/or surface hoar over a crust remains a concern at treeline. This layer will need time to adjust to the new snow load.
Aspects: All aspects.
Elevations: Treeline.
Likelihood: Possible
Expected Size: 1 - 3