Regions
Kootenay Boundary.
Storm slabs should be getting less and less sensitize to human triggering, but you need to exercise due diligence and carefully investigate the new/old snow interface before committing to the bigger more complex lines.
Weather Forecast
After a very active pattern that has delivered storm after storm, the pendulum is swinging to the opposite end of the spectrum. Wind is the big story for the forecast period, but we are not expecting any new snow in the Kootenays until at least the New Year. CHRISTMAS: No snow expected, freezing level at valley bottom, light N/NW winds. BOXING DAY: No new snow, freezing level at valley bottom, light S/SW winds. SUNDAY: No significant precipitation, freezing level at valley bottom, light SW winds at treeline, strong SW winds at ridgetop.
Avalanche Summary
Recent avalanche activity has been limited to small loose snow avalanches on steep features and small wind slabs.
Snowpack Summary
30 to 60cm of storm snow is slowly settling into a very soft slab that rests on the mid-December weak layer. This layer is just a crust in most places, but in Kootenay Pass there is a surface hoar interface on or just above this crust that is most prevalent between 1800 and 2000m. At treeline the early December crust is down around 50 to 100cm, and it's thick and supportive nature is likely capping any deeper weaknesses in most places. However, recent observations from the Nelson area indicate that there are facets on this crust, so it's an interface to watch as we move into the New Year. The lower snowpack is thought to be well settled.
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.