Regions
Kootenay Boundary.
Weather Forecast
Tuesday: Light snowfall with a couple of centimetres accumulation, freezing levels dropping throughout the day to valley bottoms, and strong westerly mountaintop winds. Wednesday: Mostly clear and dry, freezing levels in valley bottoms, and moderate northerly winds. Thursday: Winds are expected to shift to westerlies as cloud cover increases.
Avalanche Summary
Recent reports include several human triggered relatively harmless thin soft wind slab avalanches running fast and loose on large surface hoar.
Snowpack Summary
10-15 cm low density snow sits above a weak layer of large surface hoar and/or facets, with and associated crust on sun-exposed slopes. At present, the snow above this weak layer is not sufficiently deep or cohesive for large slab avalanches. We typically see dangerous slab avalanches start to occur when the depth to the weak layer reaches approximately 40cm. Below these potential near surface issues, the mid pack is strong. The basal snowpack layers are faceted, however, we have not received any recent reports of associated instabilities.
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.