Avalanche danger will drop as the temperature continues to cool, however, a widespread melt-freeze crust will make for challenging riding.
Weather Forecast
A ridge of high pressure will prevail through until Saturday over the southern half of BC, leading to mainly sunny skies in the mountains with extensive low cloud in the valleys. Freezing levels may rise to 1500m during the day but will return to valley bottom overnight. Winds will be mainly light from the west.
Avalanche Summary
As the temperature drops I expect that avalanche activity will slow down. The recent snow, rain, and wind were a great test of buried persistent weaknesses in the snowpack and resulted in a widespread avalanche cycle. The mid-January surface hoar layer was responsible for the majority of the recent avalanche activity although there have been reports from the Selkirks of occasional releases to ground and on the mid December layer.
Snowpack Summary
I suspect that freezing levels rose to between 2400 and 2800m during the recent warm spell and that rain saturated the upper snowpack. Above this elevation the surface is heavily wind effected. A breakable crust already exists in the alpine and as the freezing level continue to drop a widespread melt freeze crust is forming on all aspects and elevations. Reports indicate that riding conditions at lower elevations range for challenging to desperate. The mid-January surface hoar remains a concern and can be found down between 30 and 80 cm, however, I suspect that it may have been destroyed at lower elevations. The midpack is broken by the mid-December surface hoar layer that is now 80 to 140cm below the surface.
Problems
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.