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 Persistent Slabs.
wlewis,
Avalanche Canada
Wind slabs have formed at higher elevations, approach ridgelines and mid slopes rollovers with caution.
Summary
Confidence
Avalanche Summary
Avalanche activity on Thursday was limited to north facing slopes at treeline and above. Natural avalanches were reported to size 2 in steep terrain features. One wind slab was remotely triggered, indicating touchy conditions.
Snowpack Summary
20-30 cm of storm snow has likely been redistributed by southwesterly winds into wind slabs on north and east facing slopes. There may be a spotty layer of surface hoar about 15-30 cm below the snow surface in sheltered terrain, at treeline and below.
A layer of facets buried at the end of November can be found 100 to 200 cm below the surface. The snowpack depth varies between 150 and 250 cm at treeline.
Weather Summary
Thursday Night
Cloudy with 5-10 cm of snow, southwest winds 30-50 km/h. Freezing levels at valley bottom.
Friday
Cloudy with up to 5 cm of snow, southerly winds 20-40 km/h, treeline temperature -7 °C. Freezing levels at valley bottom.
Saturday
Mainly cloudy with up to 10 cm of snow, southerly winds 50-80 km/h. Freezing levels rise to 500 m, treeline temperature -5 °C.
Sunday
Cloudy with moderate snowfall. Southerly winds, 60-90 km/h. Freezing levels rise to 1000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
Problems
Wind Slabs
Fresh wind slabs formed on Thursday are likely still reactive to human triggers.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A deeply buried layer of facets sitting on a hard crust 100-200 cm below the snow surface is likely unreactive. It may be triggered from a thin spot or by a very heavy load such as a cornice failure.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 22nd, 2023 4:00PM
