Avalanche Forecast
Issued: Dec 25th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
zryan,
Avalanche Canada
Avoid wind-loaded areas and keep in mind that a weak layer of surface hoar is still buried within the range for large human-triggered avalanches.
Summary
Confidence
Avalanche Summary
A natural avalanche cycle occurred on Friday evening. Numerous large (size 2 to 3) storm and wind slabs were reported from the alpine and treeline on a variety of aspects.
Reactivity persisted into the weekend, with numerous skier-triggered wind slabs up to size 2 reported in the alpine and treeline. Check out this MIN for an example. A notable skier-triggered size 2 persistent slab occurred in the Selkirks east of Revelstoke on a northeast aspect in the alpine on Saturday.
Snowpack Summary
Recent storm snow has been redistributed into wind slab near ridge crests by strong winds. Below treeline a new crust is on or near the surface.
The mid pack contains several layers of note; a layer of surface hoar and a crust down 20 to 50 cm, a significant crust from the early December rain event down around 60 cm and a layer of surface hoar down 60 to 100 cm.
The make up of the lower snowpack is variable throughout the region, in shallower snowpack areas, basal facets may exist
Weather Summary
Monday Night
Increasing cloud cover with isolated flurries. Alpine wind southwest 30 to 60 km/h. Treeline temperature -4 °C.
Tuesday
Cloudy with snowfall, up to 5 cm of accumulation. Alpine wind southwest 30 to 60 km/h. Treeline temperature -4 °C. Freezing level rising to 800 m.
Wednesday
A mix of sun and cloud with isolated flurries. Alpine wind southeast 30 to 70 km/h. Treeline temperature -4 °C.
Thursday
Cloudy with snowfall, up to 5 cm of accumulation. Alpine wind south 30 to 60 km/h. Treeline temperature -3 °C. Freezing level rising to 1000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs are most reactive during their formation.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Problems
Wind Slabs
Fresh, reactive wind slabs may form throughout the day in lee features at treeline and above.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A layer of surface hoar is down 60 to 100 cm in the snowpack. This layer is still concerning where a thick crust is not found above it.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2023 4:00PM
