Regions
Kootenay Boundary.
The slopes with the best riding conditions are also the most dangerous - steep alpine slopes
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Thursday: Mainly cloudy with light snow flurries bringing another 5cm of snow. Freezing levels in valley bottoms and moderate southerly ridgetop winds. Friday: Mainly cloudy with light snow flurries bringing another 5cm of snow. Freezing levels in valley bottoms and moderate southerly ridgetop winds. Saturday: Increasing snowfall with 10-15cm possible by the end of the day. Freezing levels in valley bottoms and moderate southerly winds.
Avalanche Summary
Reports from Tuesday and Wednesday morning include numerous explosive triggered storm slab avalanches and natural loose wet avalanches up to Size 2.
Snowpack Summary
Heavy rain to treeline elevations and wet snow above saturated and loaded the upper snowpack, forming a new crust which now has light amounts of fresh snow on top. Weaknesses linger within the recent snow as well as at old snow surface interfaces, which consists of facets, surface hoar, and/or a crust at upper elevations (especially on southerly aspects). The most critical of these is surface hoar buried early December (now likely down 50-100cm), which has the potential for remote triggering, extensive releases and prolonged sensitivity to triggers. It is likely lurking in most sheltered areas treeline and below. The thick mid-November crust is just under this weakness.
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.