Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 12th, 2022–Mar 13th, 2022

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

South Coast Inland.

Watch for pockets of wind slab at upper elevations. Don't forget about a buried weak layer that remains triggerable.

Confidence

High -

Weather Forecast

Saturday night: Cloudy with snowfall, accumulation 2 to 5 cm, 20-30 km/h south wind, alpine temperature -5 C. Freezing level 900 m.

Sunday: Cloudy with snowfall, accumulation 2 to 5 cm, 20 km/h southwest wind, alpine temperature -3 C. Freezing level 1600 m.

Monday: Cloudy with snowfall, accumulation 5 to 15 cm, 40-60 km/h southwest wind, alpine temperature -3 C. Freezing level 1600 m.

Tuesday: Cloudy with snowfall, accumulation 5 to 15 cm, 40-60 km/h southwest wind, alpine temperature -3 C. Freezing level 1500m.

Avalanche Summary

No new avalanches reported on Thursday or Friday.

A rider triggered a persistent slab avalanche along the Duffey on Wednesday, occurring at 2000 m on a northeast aspect. Another suspected persistent slab avalanche was triggered by a rider on Tuesday in the north of the region. Both slabs were around 30 to 40 cm thick, resulting in small avalanches (size 1 to 1.5). It remains possible that humans could trigger this layer, where it exists.

Looking forward, wind slabs may begin to form on Friday and into the weekend, which may not bond well to underlying layers.

Snowpack Summary

Small amounts of new snow and southwest wind have likely formed small wind slabs in lee terrain features. The snow accumulates onto variable surfaces. On sun-exposed slopes and on all aspects at low elevations, the snow will build on a hard melt-freeze crust. Elsewhere, it will fall onto previously wind-affected snow at higher elevations and perhaps a thin layer of surface hoar or faceted snow in sheltered areas.

Around 30 to 60 cm deep, sugary faceted grains may be found around a melt-freeze crust that formed February in the north of the region (e.g., Duffey, Hurley). To date, the layer has been most prevalent on north to northeast aspects around 1900 to 2100 m. This layer should be treated as suspect anywhere it exists. Check out this forecaster blog for more info. Various crusts may be found in the south of the region (e.g., Coquihalla, Manning) but reports suggest they are bonding to the snowpack and are not an avalanche concern.

There are no deeper concerns at this time.

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
  • Although their spatial distribution is isolated, wind slabs are reactive.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Problems

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.

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.