Heavy snowfall through Sunday night into Monday and Tuesday combined with strong winds and warm temperatures will keep the avalanche danger elevated through the forecast period
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Monday: Snow heavy at times, accumulations from Sunday night through Monday 30-40cm / Moderate to strong southwest wind / Alpine temperature 0 / Freezing Level 800m Tuesday: Flurries or scattered showers at lower elevations, accumulations 5-10cm / Moderate to strong west wind / Alpine temperature of 1Wednesday: Cloudy with scattered flurries / Moderate to strong south wind / Alpine temperature 2
Avalanche Summary
Expect avalanche activity with new snowfall accumulating Sunday night through the day Monday combined with moderate wind and warming temperatures. Last weekend 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.
Snowpack Summary
New moist or wet new snow overlies the variable old snow surface from late last week, which includes well settled snow on southerly aspects, loose snow on shaded aspects, isolated pockets of surface hoar, and sun crusts on steep southerly aspects. With the potential for buried surface hoar means storm snow weaknesses from this latest storm 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.