Avalanche Forecast

Moderate - Due to the number of field observations on Sunday

An Arctic front pushes southward on Monday bringing cold, dry conditions for the next few days. Mostly sunny conditions are expected on Monday with light alpine winds from the northwest and treeline temperatures around -15C. Conditions are expected to remain similar on Tuesday and Wednesday with mostly sunny conditions, light northerly winds in the alpine, and treeline temperatures falling as low as -20C.

On Saturday, natural storm slab and wind slab avalanches up to size 2 were reported in the region. These were typically 30-45cm thick and occurring on northerly aspects in the alpine and at treeline. Explosives and ski cutting were also producing storm slab avalanches size 1-2. These were also primarily occurring on steep northerly aspects in the alpine and at treeline.  On Monday, the storm slabs that formed over the weekend are expect to remain reactive to human-triggering. These storm slabs are expected to be most reactive on north through east aspects in the alpine as a result of recent wind loading. Isolated persistent slab avalanches on the mid-November crust will remain an ongoing concern and appears to be a low probability, high consequence problem which likely would require a heavy trigger or triggering from a thin area.

The weekend storm system brought 30-60cm of new snow to the region with strong southwest wind in the alpine. The resulting storm slabs are thickest and most reactive in leeward features in wind exposed terrain. In some areas, the recent storm snow may sit over a layer of small surface hoar. There is some uncertainty regarding the distribution of this surface hoar in the region but it was reported in a couple locations in the Monashees west of Revelstoke. The mid-November crust is now typically down 1-1.5m in the snowpack. Test results on this layer have been highly variable ranging from sudden and easy to unreactive. While there has not been much avalanche activity on this layer yet, it has many professionals concerned. It will be important to track how this layer evolves, especially with the upcoming period of cold weather. Below the crust the snowpack is generally well settled and is reported to be moist at lower elevations.