Regions
Northwest Coastal.
Confidence
Fair - Intensity of incoming weather is uncertain for the entire period
Weather Forecast
Friday: Moderate SW winds. Alpine temp around -6. Light snow. Saturday: Light to moderate NW winds. Freezing level at valley bottom. Very light snow.Sunday: Moderate SW winds. Freezing level at valley bottom. Light snow starting late in the day.
Avalanche Summary
A skier triggered a small hard wind slab on a steep north-facing roll near treeline on Tuesday. No avalanches have been reported since then.
Snowpack Summary
Light new snow is landing on variable surfaces including wind slabs and surface facets. Some alpine slopes are heavily scoured. Cornices are fragile. A layer of surface hoar buried in the upper metre of the pack has been observed in the Shames backcountry. The mid-pack is generally well settled. Near the base of the snowpack, a crust/facet layer sometimes gives hard, sudden results in snowpack tests. This weakness is unlikely to be triggered by a single person, but it remains possible with a very heavy load (e.g. cornice fall) or from a thin-spot trigger point.
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.