Regions
Kootenay Boundary.
As this past week's storm snow continues to settle it will still be important to evaluate the bond between the old snow surface and the new snow. There is still potential for a weak sliding layer in isolated sheltered areas.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Saturday
Weather Forecast
Friday: Flurries, accumulation 5-10cm / Light east wind / Alpine temperature -7Saturday: Flurries, accumulation 5-10cm/ Light east wind / Alpine temperature -7Sunday: Mainly cloudy / Light west wind / Alpine temperature -9
Avalanche Summary
Recent reports in the past few days indicate a few wind slabs avalanches triggered from explosives control running on the storm/old snow interface to size 2 at tree line and above.
Snowpack Summary
20-40 cm of new snow from earlier in the week has buried old wind slabs, facets and surface hoar. There is a bit of uncertainty regarding how the new snow is bonding to old surfaces which formed during last week's cold clear period. Moderate to strong winds have loaded leeward features with wind slabs. A widespread crust that was buried in November is typically down 80-100cm. Recent tests show variable results with this persistent weakness. Some show results as hard and resistant and other show it may have the propensity to propagate if triggered from thin rocky areas.
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.