Avalanche Forecast
Issued: Jan 3rd, 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.
llarson,
Avalanche Canada
Rider-triggered avalanches are still possible where the persistent weak layer is closer to the snow surface in shallow snowpack areas.
Summary
Confidence
Avalanche Summary
A large (size 2) natural wind slab was reported that started in a steep, alpine terrain feature. Explosive control triggered a small, storm slab in a steep alpine feature.
A rider triggered a small avalanche in an opening, as shown in this MIN. The avalanche likely released on one of the weak layers described in the Snowpack Summary and shows that this layer could still be triggered in specific terrain. Caution should be taken in challenging or complex terrain given the uncertainty and consequence of large avalanches.
Snowpack Summary
20 to 50 cm of snow is being redistributed by light winds in open areas developing wind slabs in lee terrain features in the alpine and treeline. A hard melt-freeze crust can be found up to treeline elevations formed by rain on December 26. A surface crust formed during yesterday's sunny skies may be found up to around 1600 m on all aspects and up to ridgetop on sun-exposed slopes.
Two deeper layers of surface hoar and facets could still be triggered in specific terrain. These include a 40 to 80 cm deep layer buried mid-December and an 80 to 150 cm deep layer buried mid-November. These layers are generally deeper around Fernie and shallower towards Sparwood and Elkford. The layers may be easier to trigger where they are buried within the top 100 cm of the snowpack.
Weather Summary
Tuesday Night
Increasing cloud coverage with a trace of snow, 20 km/h southwest wind, treeline temperature -9 °C.
Wednesday
Mix of sun and cloud, trace of new snow, 20 to 30 km/h southwest wind, treeline temperature - 12 °C.
ThursdayMostly cloudy, trace of new snow, 10 to 15 km/h south wind, treeline temperature -5 °C.
FridayMostly cloudy, 3 - 5 cm new snow, 20 to 30 km/h southwest wind, treeline temperature -5 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Be especially cautious as you transition into wind affected terrain.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
Problems
Wind Slabs
Southwest winds will continue to redistribute low-density snow in open areas in the alpine and treeline.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Buried weak layers are likely gaining strength but the possibility of triggering a large persistent slab avalanche remains. There are two weak layers, both composed of surface hoar and facets, anywhere from 40 to 150 cm deep. It may be more likely to trigger these layers where they are buried relatively shallow.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 4th, 2023 4:00PM
