Avalanche Forecast

Archived

Feb 20th, 2025–Feb 21st, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Northwest Coastal, Northwest Inland, Boundary, Stewart, Kispiox, Ningunsaw, Ningunsaw, Ningunsaw.

Use extra caution in wind-affected terrain

Wind slabs have been sensitive to rider traffic due to underlying weak layers.

Confidence

Moderate

Avalanche Summary

On Wednesday ski cutting produced numerous size 1 wind slab avalanches. These avalanches were on north aspects at treeline and above, they were easy to trigger due to surface hoar beneath.

Snowpack Summary

By Friday morning up to 20 cm of recent storm snow may have fallen with southerly wind forming deeper deposits on northerly aspects. This recent snow will overlie a variety of surfaces including a layer of surface hoar in sheltered terrain and wind-affected snow or a crust in exposed terrain.

In sheltered terrain 40 to 70 cm of faceted snow overlies a crust and layer of surface hoar from late January.

Another layer of surface hoar was buried near the middle of January and can be found 50 to 100 cm deep.

A weak layer of facets and a crust from early December varies in depth from 100 to 300 cm. This layer remains a concern in this region.

Weather Summary

Thursday Night

Cloudy with around 5 cm of snow. 20 to 40 km/h south ridgetop wind. Treeline temperature -3 °C.

Friday

Cloudy with around 5 cm of snow. 20 to 40 km/h southeast ridgetop wind. Treeline temperature -3 °C.

Saturday

Cloudy with 15 to 20 cm of snow. 30 to 50 km/h southeast ridgetop wind. Treeline temperature -2 °C.

Sunday

Mostly cloudy with 20 cm of snow. 20 to 40 km/h south ridgetop wind. Freezing level rising to 1400 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.