Regions
South Coast Inland.
Recently formed wind slabs may become reactive with solar radiation on Wednesday. Keep an eye on the sun and analyze each slope for patterns of wind effect before choosing your line.
Confidence
High - The weather pattern is stable
Weather Forecast
Wednesday: Sunny with cloudy periods and no new snow. Winds moderate from the northeast. Possible alpine temperature inversion with alpine temperatures to -12 in the south of the region and -7 in the north.Thursday: Cloudy with sunny periods and no new snow. Winds light from the southwest. Freezing level to 300 metres with alpine temperatures around -6.Friday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light to moderate from the southwest. Freezing level to 600 metres and alpine temperatures around -7.
Avalanche Summary
Evidence of a natural avalanche cycle was observed in the Duffey Lake area on Monday, where several natural Size 1-2.5 avalanches were observed to have run over Sunday night. Slab depths ranged from 20-60 cm and although most avalanches had slid on southwest aspects, southeast, east, and northeast aspects were also represented. A MIN report from Monday also details a skier triggered Size 1.5 avalanche on Vantage Peak, notable for its approximately 100 cm crown depth revealing significant loading from recent winds.
Snowpack Summary
Most parts of the region saw 60-90 cm new snow last week, which is reported to be generally bonding well to underlying snow. With that said, the critical issue under our current conditions is the wind slab problem that exists in wind-exposed areas. Below the new snow, a facet/surface hoar layer that was observed in the Duffey Lake area does not seem to have turned into a major concern. For low snow areas such as the Chilcotins, another concern is a layer of faceted snow from mid-December that is buried under approximately 50 cm of snow. This mid-December interface is now down over 1 m in most other areas and is generally considered to be stable, except in shallow snowpack areas as mentioned above, where snowpack tests indicate it could still be a viable failure plane.
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.