Regions
Northwest Coastal.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
Friday: Flurries are possible, but should stay mostly dry. Freezing level around 300 m. Ridgetop winds initially 30-50 km/h, easing through the day. Saturday: Around 10 cm new snow is expected. Freezing level around 500 m. Winds moderate SW'ly. Sunday: Light precipitation. Freezing level around 200 m. Winds easing to light.
Avalanche Summary
Few observations, due to the bad weather. It is likely there are avalanches occurring in steep alpine terrain we have not heard about. On 31st December, there were reports of a few size 1 avalanches triggered on a layer of surface hoar layer buried 30 cm below the surface in the Shames backcountry.
Snowpack Summary
Recent storm snow amounts vary from 20 to 50cm and the bond between the new snow and the old is likely to be poor in many places. Winds have been strong southwesterly to southeasterly. These have set up touchy wind slabs in many exposed lee areas. There are two surface hoar layers in the upper snowpack. The upper one formed at the end of December and is buried approximately 30 cm below the surface. Professionals have reported easy, sudden planar compression test results on this layer and it has been reactive to skier-triggering. The lower one formed at the beginning of December and is buried approximately 90 cm below the surface. Hard, planar compression tests have been reported on this layer. Near the base of the snowpack, a crust/facet layer continues to give hard, sudden results to no 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
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.