Archived advisory related to an incident, not current

Date Issued: Fri, January 10, 2025 at 16:00 PT
Valid Until: Sat, January 11, 2025 at 16:00 PT
Prepared by: Avalanche Canada

Keep an eye on changing conditions. Small wind slabs may have formed near ridge crests.

Use extra caution in shallow snowpack areas where triggering avalanches is more likely.

Danger Ratings
Saturday (Jan 11), Sun and Mon

Alpine, Treeline: 2 - Moderate
Below Treeline: 1 - Low

Terrain and Travel Advice

    Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
    Recent wind has varied in direction, so watch for wind slabs on all aspects.
    Avoid thin areas like rocky outcrops where you're most likely to trigger avalanches on deep weak layers.
    Seek out sheltered terrain where new snow hasn't been affected by wind.

Problems

Avalanche Problem 1: Wind slab
Elevation: Treeline, Alpine
Slopes: North, Northeast, East, Southeast, south, Southwest, West, Northwest
Chances of Avalanches: Possible - Likely
Expected Size: Small - Large

The wind has come from a variety of directions over the past couple days. Small wind slabs could be found on all aspects in terrain at treeline and above elevations.

Avalanche Problem 2: Persistent slab
Elevation: Treeline, Alpine
Slopes: North, Northeast, East, Southeast, south, Southwest, West, Northwest
Chances of Avalanches: Unlikely - Possible
Expected Size: Small - Large

The weak layer from early December remains a concern in shallow snowpack areas.

Avalanche Summary

Small natural and human triggered wind slab avalanches continue to be reported in the region. These avalanches have been on west and south aspects at treeline and above.

On Wednesday a small skier triggered  persistent slab Avalanche was reported on Mount Goldie. This avalanche likely released on the weak layer from early December. 

Snowpack Summary

New wind slabs have likely formed as a result of moderate southwest winds and light snowfall.

The upper snowpack contains a variety of layers including one or more surface hoar layers just below the surface in sheltered terrain and a crust on or near the surface on solar aspects.

A weak layer buried in early December can be found down 30 cm in shallow areas and as much as 120 cm in deep snowpack areas. On shaded slopes, it consists of weak surface hoar or faceted crystals, while on south-facing slopes, it combines a sun crust with facets.

The snowpack base is composed of a thick crust and facets in many areas.

Weather Summary

Friday Night: Mostly cloudy with snow flurries 1 to 2 cm. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -7 °C.

Saturday: Mostly cloudy with snow flurries 1 to 2 cm. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -9 °C.

Confidence: Moderate, Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.