Avalanche Forecast

Archived

Dec 22nd, 2025–Dec 23rd, 2025

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 unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Stick to sheltered, lower-angled terrain for the best and safest riding.

If over 25 cm falls overnight, think HIGH avalanche danger.

Confidence

Moderate

Forecast precipitation (either snow or rain) amounts are uncertain.

Avalanche Summary

On Sunday, a snow cat in the Whistler area triggered a size 2 persistent slab on a northwest aspect in the alpine. This avalanche failed on the mid november crust, down 60 to 160 cm. Skiers were also able to trigger size 1 storm slabs, mainly in wind-loaded areas, in the alpine and treeline.

Looking forward to Tuesday, reactive storm slabs continue to be primed for human-triggering from snow and wind.

Snowpack Summary

In the past 2 days, up to 50 cm of new snow accompanied by strong southerly winds has left a variety of surfaces - wind slabs and loaded pockets in lee features, scoured rock in open terrain, and storm slabs and softer snow in sheltered areas.

This brings the past week's storm totals to over 100 cm of new snow! This new snow buries a melt-freeze crust that exists at 2200 m and below. The depth of this crust is highly variable due to extensive recent wind transport.

A crust with facets, formed in mid-November, is buried an estimated 80 to 150 cm deep. With limited observations, especially in the alpine (which did not have the same mid-pack crust development), we're not ready to rule out this layer of concern quite yet.

Weather Summary

Monday Night
Cloudy. 20 cm of snow. 50 to 80 km/h south ridgetop wind. Treeline temperature -6 °C.

Tuesday
Mostly cloudy. 5 to 15 cm of snow. 30 km/h south ridgetop wind. Treeline temperature -7 °C.

Wednesday
Mix of sun and clouds. 2 to 4 cm of snow. 10 km/h southeast ridgetop wind. Treeline temperature -7 °C.

Thursday
Mix of sun and clouds. 1 to 2 cm of snow. 10 km/h southeast ridgetop wind. Treeline temperature -6 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Don't let the desire for deep powder pull you into high consequence terrain.
Be especially cautious as you transition into wind-affected terrain.
Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.