Avalanche danger will increase as an intense winter storm hits the eastern slopes of the Rockies.
Storm slabs will become thicker and easier to trigger as snow accumulates over the next few days. Expect natural avalanches at higher elevations and in wind affected terrain.
TUESDAY NIGHT: Flurries with accumulations of 10-15 cm of snow on the Alberta side of the continental divide, less in BC, 50-70 km/h wind from the northeast, alpine temperatures drop to -17 C.
WEDNESDAY: Flurries continue throughout the day with another 10-30 cm of snow, 50-80 km/h wind from the northeast, alpine temperatures around -17 C.
THURSDAY: Flurries on Wednesday night bring another 5-20 cm of snow then flurries ease and skies clear by Thursday afternoon, 20-40 km/h wind from the northeast, alpine temperatures around -15 C.
FRIDAY: Sunny, light wind from the northeast, alpine temperatures around -12 C.
The current storm will likely cause a cycle of natural avalanches on Wednesday and/or Thursday. The greatest danger will be in areas that receive the greatest accumulations of new snow, which will likely be the eastern slopes of the Rockies. Human triggering will also be very likely in these area.
Prior to the storm, no avalanches were reported in the South Rockies region, however small wind slab avalanches have been reported in the neighbouring Lizard Flathead, Kananaskis, and Banff regions (see this MIN report for an example).
An intense storm will rapidly change the snowpack. 30-50 cm of new snow is possible by Wednesday afternoon. Strong wind will scour some terrain features down to rocks and old crusty snow while creating extra deep deposits on other terrain features. The new snow is falling on a highly variable early season snowpack. Some alpine terrain already has 50-100 cm of snow while other alpine terrain features and lower elevations have had no snow prior to this storm. In areas that had prior snow, there could be a crust in the snowpack that could act as a sliding layer for the snow above it. Because of the uncertainty about the snowpack structure it is best to avoid or be extremely cautious travelling in avalanche terrain during the storm.
