Regions
Kootenay Boundary.
The story for the next few days will be the colder weather, however continue to consider the reactivity of recently buried weak layer.
Confidence
High - The weather pattern is stable
Weather Forecast
SUNDAY Night: Mainly cloudy with scattered flurries, moderate northeast wind, alpine temperature -17 C.MONDAY: Mix of sun and cloud, light to moderate northeast wind, alpine temperature -12 C.TUESDAY: Mix of sun and cloud, light northeast wind, alpine temperature -13 C.WEDNESDAY: Mix of sun and cloud, light northwest wind, alpine temperature -15 C.
Avalanche Summary
Reports from Saturday include several natural size 1.5-2 storm slab avalanches and explosives triggered size 2-2.5 storm slab avalanches on southerly and northerly aspects up to 2200m. Additionally, there were several observations of naturally triggered size 2 wind slab avalanches on northerly aspects in the alpine.
Snowpack Summary
10-30 cm of new snow sits on variety of snow surfaces, which may include wind crust in wind exposed areas, a crust on solar aspects to mountain top and weak feathery surface hoar in sheltered areas treeline and below. In some places this surface hoar is reported be sitting on a crust.40-80 cm below the snow surface, expect to find another crust on south aspects and another layer of feathery surface hoar crystals in sheltered and shaded areas. This deeper layer of surface hoar may be most reactive at treeline elevations on shady aspects. The remainder of the snowpack is generally well-settled and strong.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.