Avalanche Forecast
Issued: Dec 21st, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
TH,
Avalanche Canada
Strong winds will keep the danger ratings elevated Friday.
Remember that this is a relatively shallow and weak snowpack.
Early season hazards are a real concern. Travel BTL is poor.
The weak snow at the base of the snowpack dictates the need for conservative terrain selection.
Days are short: aim to be back to the trailhead by about 4 PM
Summary
Confidence
Avalanche Summary
Both Sunshine Village Snow Safety and Lake Louise Avalanche Control reported only a few, 10-20cm deep, wind slabs that were generally observed local to their shots Thursday.
As these teams are working hard to open new terrain, they would remind visitors, especially those who plan to visit the slack country near their resorts, to keep it safe over the holidays given the thin snowpack they are working with, and the crowds that can be expected.
Snowpack Summary
SW winds have created wind slabs in alpine and exposed treeline locations.
A thin mid-pack is generally carrying skis right now. This often includes a rain crust that is up to 7 cm thick and has been observed as high as 2300m (although it is not as high in northern areas).
The lower snowpack is facetted and weak.
Moist surface snow was observed as high as 2000m Wednesday and Thursday: expect a crust in the AM.
Treeline snowpack depths range from 50-95cm.
Weather Summary
Mild temperatures continue with freezing levels approaching 2000m again Friday. Alpine winds will be SW 50- 65km/h. While up to 8cm of snow is possible west of the divide by Saturday AM, mostly flurries can be expected elsewhere.
A cold front will arrive on Friday night with winds shifting west and diminishing to 35 km/h. Clearing and cooling to follow.
For more information, click Mountain Weather Forecast.
Terrain and Travel Advice
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Problems
Wind Slabs
SW winds have created thin wind slabs in alpine, and some exposed treeline locations. Incoming strong SW winds Friday may contribute to slab formation. If initiated, these slabs may step down to the deep persistent layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The bottom layers of the snowpack are facetted and weak. Human triggering could result in a large avalanche. It is easy to dig down to these layers given the thin snow coverage: test the snow before venturing into terrain with any consequence.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 22nd, 2023 4:00PM
