There have been many close calls with avalanches this week.
The avalanche danger remains elevated, please plan your objective accordingly.
Strong to extreme winds Saturday will add to the wind slab problem at alpine and treeline elevations. Some of these slabs may be sitting over facets and easier to trigger. In thinner snowpack areas, these may initiate deeper layers which can run far.
The midpack Dec. 2 crust and facets is mainly a concern in thinner snowpacks. We saw an increased in reactivity during the recent warm spell. We are uncertain on how the cooling trend will effect the reactivity of this avalanche problem.
The Westerly flow will gradually weaken through the beginning of the week. Winds for Sunday and Monday will remain in the strong range at ridge top. Temperatures will stay warm with freezing levels near valley bottom. Forecasted precipe values range from 10cm to 20cm . We should see a sharp change Tuesday as cold, clear, calm weather arrives.
10-20cm of settled storm snow with strong to extreme winds has added to windslabs at treeline and above. These overlie facets in many places. The Dec. 2 crust and facets are anywhere from 130cm deep in the snowpack in thicker parts, and half that depth in thinner snowpack areas such as Mt. Stephen and Mt. Dennis.
Saturday Parks Canada VS responded to a natural avalanche on Mt Stephen that deposited a significant amount of snow on a train line and trapped a train in the debris pile. Avalanche control on Friday produced numerus results to sz 2.5, triggering both wind slabs and persistent slabs.
