Avalanche Forecast
Issued: Dec 18th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
Avalanche Canada,
Avalanche Canada
Give the recent new snow some time to settle and bond. There is uncertainty with how a buried layer of surface hoar is reacting to the recent new snow load.
Summary
Confidence
Moderate
Avalanche Summary
As of publishing time on Wednesday there were several reports of size 2-3 explosives triggered storm slab avalanches. Other reports indicate numerous natural wind and storm slab avalanches up to size 2.5 running in steep alpine terrain.
There were two reports of size 2 to 2.5 persistent slab avalanches running on northerly aspects between 2200 and 2300 m in the south of the region in the Selkirk range. Both were storm snow avalanches stepping down to buried surface hoar.
Snowpack Summary
15-30 cm of new snow fell Tuesday night through Wednesday and is being redistributed by west southwest winds in the alpine and open treeline.
A surface hoar layer formed in early December is now buried 50 to 90 cm and is most prevalent between the 1700 to 2200 m elevation bands. We're tracking this layer as the load (and resulting slab) builds above it. We may see reactivity increase if the load above reaches a critical threshold.
Weather Summary
Wednesday NightCloudy with isloated flurries, accumulation 1 to 3 cm. 25 to 50 km/h west ridgetop wind. Treeline temperature -6 °C.
Thursday
Mostly cloudy with some sunny breaks. 20 to 30 km/h southwest ridgetop winds. Treeline temperature -5 °C.
Friday
Mostly cloudy with scattered flurries, accumulation 5 to 10 cm. 20 to 40 km/h southwest ridgetop winds. Treeline temperature -3 °C.
Saturday
Mostly cloudy. 20 to 50 km/h southwest ridgetop winds. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be alert to conditions that change with elevation, aspect, and exposure to wind.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Storm Slabs
Storm slabs may still be reactive to rider triggers on Thursday.
A surface hoar layer buried early December is 40 to 80 cm down from the snow surface. There is uncertainty with how it is reacting to the recent new snow load.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 19th, 2024 4:00PM
