Avalanche Forecast
Issued: Dec 22nd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
mconlan,
Avalanche Canada
Stormy weather returns, bringing uncertainty with how the weak snowpack will react to warmer air and more snow.
Summary
Confidence
Moderate
Avalanche Summary
A few small natural and rider-triggered wind slab avalanches released on Wednesday, generally on north to east aspects in the alpine.
The latest persistent slab activity occurred December 18. The buried weak layers described in the Snowpack Summary could become touchy again with warmer weather and new snow that is forecast for the coming days.
Snowpack Summary
Snow, strong wind, and a warming trend will start to form new wind slabs in lee terrain features in wind-exposed terrain. Around 20 cm of snow overlies a widespread weak layer of surface hoar crystals and a melt-freeze crust on sun-exposed slopes.
Two problematic layers exist around 40 and 70 cm deep, consisting of surface hoar, faceted grains, and/or a melt-freeze crust. Avalanches have been most prominent between 1700 and 2200 m on all aspects. Read our forecaster blog for managing a persistent slab problem.
Weather Summary
Thursday Night
Increasing clouds with early-morning snowfall, accumulation 1 to 3 cm, 20 km/h south wind, treeline temperature -22 °C.
Friday
Cloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h southwest wind, treeline temperatures -17 °C.
SaturdayCloudy with snowfall, accumulation 10 to 20 cm, 30 to 60 km/h southwest wind, treeline temperatures -8 °C.
SundayCloudy with snowfall, accumulation 5 to 15 cm, 20 to 40 km/h southwest wind, treeline temperatures -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Carefully evaluate steep lines for wind slabs.
Problems
Persistent Slabs
Two weak layers are buried at a prime depth for human triggering within the top metre of the snowpack. Most avalanches to date have released between 1700 and 2200 m. The likelihood of triggering these layers may increase in the coming days as warmer and stormier weather returns.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Pockets of wind slab may form near ridgelines from new snow and southwest wind.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 23rd, 2022 4:00PM
