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 unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Sea To Sky, Brandywine, Garibaldi, Homathko, Powell River, Spearhead, Tantalus.

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

Explosive controls produced numerous slab avalanches (up to size 2) in lee alpine terrain near Whistler on Monday and Tuesday. Several natural avalanches from the past storm cycle are still been observed across the region. One impressively large avalanche was reported on the MIN near Russet Lake.

Multiples stepp-down to the late-Jan/early Feb persistent layers around 60 to 80 cm deep were also reported from steep northerly slopes at treeline and above.

Snowpack Summary

The region received 25 to 40 cm of recent snow since Sunday, bringing the storm total to 60 to 80 cm. This overlies problematic faceted snow, or surface hoar in sheltered terrain. In exposed terrain, a sun crust is present up to 1700 m while wind-affected surfaces exist at upper elevations.

A weak layer, buried at the end of January, is now 80 to 100 cm deep in the snowpack. This may present as a crust on sunny slopes, sugary facets in most places, and surface hoar in sheltered spots. Natural avalanches and human triggering were reported on this concerning weak layer.

Weather Summary

Tuesday Night

Cloudy with isolated flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature stable around -2°C. Freezing level around 1500 m.

Wednesday

Mostly sunny. 35 to 50 km/h southeast ridgetop wind. Treeline temperature stable around +4°C. Freezing level reaching to 2500 m.

Thursday

5 to 10 cm of new snow or rain. 40 to 60 km/h southwesterly ridgetop wind. Treeline temperature 0°C. Freezing level around 1500 m.

Friday

Partly cloudy. 25 to 45 km/h south ridgetop wind. Treeline temperature +2°C. Freezing level reaching 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Continue to make conservative terrain choices while the storm snow settles and stabilizes.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

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.

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.