Avalanche Forecast
Issued: Dec 8th, 2023 4:00PM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeUp to 60+ cm of recent storm snow will take time to settle over the weaker basal layers. A spike in wind starting Saturday afternoon will be a factor in keeping the danger elevated.
Summary
Confidence
Moderate
Avalanche Summary
Avalanche control Friday produced results to size 2.5. Most were observed initiating on the basal facets, but it is unknown what layers many slid on. As skies clear, there are more observations of natural avalanches from the last few days. Most are up to size 2.5, failing on or near the ground.
Snowpack Summary
Up to 60 cm of storm snow overlies the Dec 2 layer of surface hoar, facets and a crust. Below this layer are basal facets and a crust formed in late October. We suspect there is some separation between these weak layers in the alpine, but at treeline and below, they are essentially the same layer. Snow depths range from 80-100 cm at treeline and up to 140cm observed in alpine locations.
Weather Summary
Winds will increase mid-day Saturday in the alpine to strong, starting NW and switching to SW. Temperatures will cool to -14 to -16 with mainly sunny skies. A trace of snow on Sunday with continued strong winds.
For more information, click Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
Problems
Wind Slabs
Winds will start to increase mid-day at higher elevations. With lots of snow to transport, wind slabs could form and fail quickly. Once initiated, they could trigger deeper slabs. Watch closely for their development and consider your exposure to overhead terrain in gullies.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
The lower snowpack comprises two layers. Facets and a crust lie at the base, and the Dec 2nd layer of surface hoar, facets and crust above. These layers may be separated a bit in the alpine but, in many places, are right above each other. Avalanches can be significant in size and run below treeline.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 9th, 2023 4:00PM