Avalanche Forecast

Archived

Mar 16th, 2025–Mar 17th, 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, human triggered possible.

Regions

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

The weather is shifting, but a complex snowpack remains hidden beneath the storm snow.

Verify conditions as you go and adjust terrain choices if you notice signs of instability.

Confidence

Moderate

Avalanche Summary

Two large persistent slab avalanches (size 2 to 2.5) were observed on Duffey Lake Road, failing naturally on the early March weak layer, stepping down to the mid-February layer.

On Friday, numerous solar-induced avalanches occurred in Birkenhead, including a size 3.5 persistent slab that ran full path on a northeast alpine slope.

North-facing alpine and treeline terrain continue to see several natural and human-triggered avalanche activities since the past week.

Snowpack Summary

The region received another 10 cm of new snow this weekend totaling 80 to 150 cm of storm snow in the past week. This sits on a weak layer formed in early March that consists of facets or surface hoar that overlie a crust on all aspects except high north-facing slopes. Two very large natural avalanches (up to size 3.5) were reported on this layer last Friday, one of them running to valley bottom.

Weak layers formed in mid-February and late-January are now buried 100 to 175 cm deep.

Weather Summary

Sunday Night

Partly cloudy with up to 5 cm of new snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing level at valley bottom.

Monday

Mix of sun and clouds with isolated flurries. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1000 m.

Tuesday

Mostly sunny. 15 to 25 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1200 m.

Wednesday

A mix of sun and clouds. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

If triggered, wind slabs avalanches may step down to deeper layers resulting in larger 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.
Be alert to conditions that change with elevation, aspect, and exposure to wind.

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.