Regions
Kootenay Boundary.
There are lingering wind slabs on northeast aspects, and watch for the influence of the sun on southern aspects.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Tuesday: Flurries. Mostly calm winds. Freezing level around 1600 m. Wednesday: Dry with sunshine in the morning, becoming cloudy with some flurries in the afternoon. Winds 20-30 km/h from the southeast. Freezing level around 1600 m. Thursday: 15-20 cm new snow overnight Wednesday and into Thursday. Winds light southeasterly. Freezing level around 1500 m.
Avalanche Summary
On Monday, a size 2 avalanche was ski cut in recent storm snow in the Monashees. A similar sized avalanche was also naturally triggered. On Saturday there was an accidentally triggered size 2 wind slab reported in the Valhallas. I think this kind of shallow wind slab in alpine terrain is representative of a lingering wind slab concern: localized pockets, lee and cross-loaded features, around 20 to 30 cm thick. Although not in this region, Saturday's fatal avalanche accident on Mt. Harvey (South Coast Mountains) highlights several of the risks posed by cornices: multi-ton snow boulders serve as large triggers potentially releasing big avalanches on the slopes below, and they can break well back making for tricky travel along ridge crests.
Snowpack Summary
In exposed high elevation terrain, recent moderate southerly winds and new snowfall have formed wind slabs in leeward features. At lower elevations and on sun exposed slopes, there is likely moist or wet snow sitting on top of several well bonded crust layers in the upper snowpack.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.