Avalanche Forecast

Archived

Mar 22nd, 2025–Mar 23rd, 2025

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

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 possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

During periods of high hazard, avoid all avalanche terrain.

We expect a large natural avalanche cycle with snow, strong winds, and buried weak layers.

Confidence

Moderate

Avalanche Summary

On Friday, skiers remotely triggered this very large avalanche near Vantage Peak. Explosive control in the region produced four size 2.5 persistent slab avalanches on northwest alpine features.

On Monday, two very large persistent slabs were remotely triggered by skiers and a snowcat in the Birkenhead area. They occurred on west and east alpine slopes and ran full path. Crowns were 75 to 100 cm and one of them stepped down to the mid-February week layer.

Snowpack Summary

Up to 25 cm of new snow is expected, and will be redistributed into deeper and more reactive deposits on north- and east-facing slopes by strong to extreme southwesterly winds. This overlies 15 to 30 cm of recent snow and then wind-affected snow at upper elevations and a melt-freeze crust on southerly slopes up to 2000 m. This sits over 80 to 150 cm of settling old snow.

The early March weak layer of facets or surface hoar on a crust is now down 100 to 150 cm and is present on all aspects except high north-facing slopes. Very large avalanches (size 3 to 3.5) were reported on this layer this past week.

Weak layers formed in mid-February and late-January are now buried 110 to 190 cm deep.

Weather Summary

Saturday Night

Cloudy with up to 10 cm of snow. 30 to 60 km/h southwest ridgetop winds. Treeline temperature -9 °C.

Sunday

Cloudy with up to 15 cm of snow. 30 to 40 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level rises to 1500 m by 4 pm.

Monday

Cloudy with 5 to 10 mm, falling as snow above 1500 m. 20 to 40 km/h southwest ridgetop winds. Treeline temperature 2 °C.

Tuesday

Cloudy with up to 5mm, falling as snow above 2000 m. 50 km/h southwest ridgetop winds. Treeline temperature 4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Be mindful that deep instabilities are still present and have produced recent large avalanches.
Only the most simple non-avalanche terrain with no overhead hazard is appropriate at this time.

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.