Avalanche Forecast
Issued: Dec 12th, 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.
mbender,
Avalanche Canada
There is still uncertainty with where persistent slabs may still be reactive after last week's rain event. Be sure to post observations on the Mountain Information Network.
Summary
Confidence
Moderate
Avalanche Summary
There are no new avalanches to report in past few days.
Snowpack Summary
30-55 cm of snow sits on a 5-15 cm melt-freeze crust. Below this crust you may find moist snow to ground, or dry, possibly refrozen snow and a layer of somewhat preserved surface hoar around 60 cm deep.
Triggering this layer of surface hoar may be possible in areas where the overlying crust is thinner and less supportive. We recommend treating this layer as suspect while we await more observations.
Snow depth is generally 70-110 cm at treeline, tapering quickly below. The mid and lower snowpack may contain a weak facet layer in shallower areas.
Weather Summary
Tuesday Night
Mainly Cloudy. Light west ridgetop wind. Treeline temperature around -8 °C, with possible temperature inversion in the alpine.
Wednesday
Mainly sunny. Moderate southwest ridgetop wind. Treeline temperature around -3°C, with possible temperature inversion in the alpine.
Thursday
Mostly cloudy. Isolated flurries with 1-3 cm accumulation. Moderate to strong southwest ridgetop wind. Treeline temperature around -4°C.
Friday
Mainly cloudy. Moderate southwest ridgetop wind. Treeline temperature -5°C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Surface hoar distribution is highly variable. Avoid generalizing your observations.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- 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
Wind slabs may be triggerable by riders, especially where wind has moved snow into leeward terrain features.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
This surface hoar layer was seen after the rain storm in some areas, 4-20mm big. As the moisture in the snowpack migrates and freezes, the weak layer may melt or bond, and crusts above it may become more robust, making it harder to trigger.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 13th, 2023 4:00PM
