Avalanche Forecast

Archived

Mar 15th, 2025–Mar 16th, 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 unlikely, human triggered possible.

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.

Regions

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

An abundance of recent storm snow needs time to settle and bond.

Stick to conservative terrain and watch for changing conditions.

Rider-triggered avalanches remain likely on Sunday.

Confidence

Moderate

Avalanche Summary

With continuous storm cycles in the past week, numerous natural and human-triggered storm slab avalanches have been reported throughout the region. Near Whistler and Garibaldi Park, there were several mentions of skiers accidentally triggering large slabs from northerly to easterly alpine slopes (size 1 to 2.5) on Friday.

Rider-triggered avalanches remain a concern on Sunday.

Snowpack Summary

An additional 10 to 15 cm is expected on Saturday night, which will bring this week's storm totals to 120 to 175 cm of new snow. The storm snow is settling out rapidly and has been affected by the sun on steep southerly slopes. It sits on a weak layer formed in early March that consists of a crust on all aspects except high north-facing slopes and facets or surface hoar in some areas.

Weak layers formed in mid-February and late January are now buried 150 to 250 cm deep. We suspect these layers have mainly healed, but observations have been limited by stormy conditions.

Below this, the snowpack is well-settled and strong.

Weather Summary

Saturday Night

Cloudy with 10 to 15 cm of new snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -6 C. Freezing level 800 m.

Sunday

Mostly cloudy with up to 5 cm of new snow. 15 to 30 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1200 m.

Monday

Cloudy with 10 to 15 cm of new snow. 20 to 30 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1000 m.

Tuesday

A mix of sun and clouds. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Storm slabs in motion may step down to deeply buried weak layers and result in very large avalanches.
Cornice failures could trigger large and destructive avalanches.
Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.

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.