Avalanche danger will drop as the temperature cools, however, a widespread melt-freeze crust will make for challenging riding.
Confidence
Fair - Due to the number and quality of field observations
Weather Forecast
Freezing levels will drop to valley bottom overnight as a cold front moves across the province. A ridge of high pressure will build over the coast on Wednesday resulting in clear skies and light SW winds in the interior. A weak front will move across the province on Friday bringing isolated flurries.
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 has been responsible for the majority of the recent avalanche activity in the region, producing numerous avalanches up to size 3.
Snowpack Summary
I suspect that freezing levels rose to about 2000m during the recent warm spell and that rain saturated the upper snowpack. At higher elevations sustained moderate to strong winds have formed widespread windslabs. Snow moist enough to make snowballs with has been found near the surface below 2200m and as deep as 80cm at lower elevations. As the freezing level drops back a widespread melt freeze crust will form. I suspect that at lower elevations warm moist snow may have destroyed the mid-January surface hoar layer. Where it still exists it can be found down between 40 and 80 cm. 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.