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 and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

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

Looking ahead, we expect a large natural avalanche cycle to occur with snowfall and strong winds.

On Saturday, natural and explosive-triggered cornices failed up to size 2.

On Friday, numerous human-triggered size 1.5 storm slabs occurred in the alpine and upper treeline. An explosive-triggered size 2 storm slab was reported on the early March melt-freeze crust, on an east-facing slope in the alpine.

Thanks for sharing your observations via the MIN.

Snowpack Summary

25 to 45 cm of new snow will form touchy storm slabs and be redistributed into deeper deposits on north- and east-facing slopes. This overlies 50 cm of recent snow and then wind-affected hard surfaces at upper elevations or a melt-freeze crust on southerly slopes and at lower elevations.

A weak layer formed in early March found down 100 to 180 cm, consists of a crust on all aspects except high north-facing slopes. In some areas, a layer of surface hoar is found just above the crust.

Weak layers formed in mid-February and late January are now buried 150 to 250 cm deep.

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

Weather Summary

Saturday Night

Cloudy with 5 to 10 cm of snow. 30 to 50 km/h south ridgetop winds. Treeline temperature -6 °C.

Sunday

Cloudy with 20 to 35 cm of snow. 50 to 70 km/h southwest ridgetop winds. Treeline temperature -6 rising to 0 °C. Freezing level rising to 1500 m by 4 pm.

Monday

In the overnight period, 30 mm is expected, falling as snow above 1500 m.

Cloudy with 30 to 50 mm, falling as snow above 1500 m. 50 to 75 km/h southwest ridgetop winds. Treeline temperature 2 °C.

Tuesday

Cloudy with 10 mm, falling as snow above 2000 m. 30 to 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.
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.