Beware of wind-loaded and sun-exposed slopes where the recent storm snow has settled into touchy slabs.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
On Friday expect a mix of sun and cloud with light to moderate northerly winds and alpine temperatures around -10. Mainly cloudy for Saturday with moderate northwesterly winds and alpine temperatures around -10. Sunday should also be mainly cloudy with flurries bringing 5-10 cm by the end of the day. Ridgetop winds are expected to increase to moderate to strong westerlies and alpine temperatures increasing to -5.
Avalanche Summary
On Sunday two skiers were caught in an avalanche on the North Shore on Sunday in steep, rugged terrain. There's a photo on the North Shore Rescue Facebook page. On Saturday, a size 1.5 skier triggered avalanche was reported on the MIN. The slab was 20-30cm thick and the avalanche was 30-40m wide. Other social media from the weekend indicated highly unstable conditions. With dry, cold weather, avalanches will become harder to trigger, but I'd urge caution, since the cold temps will prolong the possibility of skier-triggered avalanches longer than is usual for this region.
Snowpack Summary
Anywhere from 30 cm (near Squamish) to 75 cm (North Shore) of fresh snow recently buried the old variable snow surface that includes well settled snow on southerly aspects, loose snow on shaded aspects, isolated pockets of surface hoar, and sun crusts on steep southerly aspects. Recent easy to moderate sudden planar snowpack tests suggest poor bonds within and under the recent storm snow. Colder than usual temperatures and the potential for buried surface hoar means these weaknesses will take longer than normal to stabilize. An old rain crust is reported to be down 150 cm in the North Shore mountains. This layer is still failing on snowpack tests, but is likely difficult to trigger in most places now.
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.