Avalanche Forecast

Archived

Dec 11th, 2025–Dec 12th, 2025

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

South Coast Inland, Birkenhead, Duffey, South Chilcotin, Stein, Taseko.

Wind slabs could step down to deeper persistent weak layers.

Start with conservative terrain and gather information before committing to slopes.

Confidence

Moderate

Avalanche Summary

On Thursday, several size 2-2.5 explosive-triggered slabs occurred in the Duffey area. these were suspected to have failed on the mid-November persistent weak layer.

On Tuesday, a deep and large slab (size 2.5-3) was observed on Matier’s East Ridge. (See photo below) This slab was also suspected of having failed on the persistent weak layer.

Snowpack Summary

Around 30 to 50 mm of precipitation fell over the last storm. Freezing levels varied, but a surface crust is likely present up to at least 1800 m.

In the alpine, strong winds scoured windward slopes, while building slabs in leeward and crossloaded terrain.

Several layers, including surface hoar, facets, and a thin crust, can be found 40 to 65 cm below the surface.

A crust with facets, formed in early November, is buried 50 to 100 cm at alpine and treeline elevations. This persistent weak layer has been the failure plane of several recent large avalanches in the region.

Snowpack height averages around 100 cm at treeline and decreases rapidly below 1500 m.

Weather Summary

Thursday Night
Mostly cloudy. 1 to 4 cm of snow. 20 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level 1100 m.

Friday
Cloudy. 2 to 4 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.

Saturday
Mostly cloudy. 1 to 5 mm of precipitation as snow or rain at treeline. 30 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1700 m.

Sunday
Mostly cloudy. 5 to 15 mm of rain at treeline. 30 km/h south ridgetop wind. Treeline temperature 1 °C. Freezing level 1900 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Stay off recently wind loaded slopes until they have had a chance to stabilize.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

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.