Avalanche Forecast

Archived

Feb 25th, 2025–Feb 26th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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 unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Regions

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

Our persistent weak layer is sensitive and will continue to be a concern with the warm weather. Dangerous avalanche conditions exist and rider-triggered avalanches are likely.

Confidence

Moderate

Avalanche Summary

Since Sunday, numerous large natural avalanches (size 2.5 to 3) were observed from steep northerly slopes at treeline and above. Several skiers-remote persistent slabs (size 1 to 2) were reported on the persistent layers down 40 to 50 cm deep while large triggers (vehicle and helicopter) remotely triggered large slabs (up to 100 cm crown). There are mentions of multiple sympathetic releases and recent step-down avalanches.

Snowpack Summary

The region received 20 to 30 cm of recent snow since Sunday, bringing the storm total to 50 to 60 cm. This is overlying various problematic surfaces including weak surface hoar or faceted grains in sheltered, shaded terrain, and sun crusts on sun-affected slopes. This layer was responsible for numerous and large remote triggers observed since Sunday throughout the region.

A layer of hard crust, buried in late January, is currently sitting beneath weak facets and less widespread surface hoar 40 to 80 cm deep. Some recent avalanches have failed on it, particularly closer to Whistler.

The snowpack below is strong.

Weather Summary

Tuesday Night

Mostly cloudy with isolated flurries. 15 to 25 km/h southwest ridgetop wind. Treeline temperature -3°C. Freezing level lowering from 1700 to 1000 m.

Wednesday

Mostly sunny. 30 to 40 km/h southwest ridgetop wind. Treeline temperature +2°C. Freezing level reaching 2200 m.

Thursday

Cloudy with isolated flurries. 40 to 50 km/h southwest ridgetop wind. Treeline temperature +2°C. Freezing level reaching 2000 m.

Friday

Mostly sunny. 15 to 25 km/h southwest ridgetop wind. Treeline temperature +2°C. Freezing level reaching 2200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
Be aware of the potential for large avalanches due to buried weak layers.
Avoid thin areas like rocky outcrops where you're most likely to trigger avalanches on deep weak layers.
Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.

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.