Choose sheltered, low-consequence terrain. Recently formed wind slabs in combination with buried weak layers necessitate a conservative approach.
Recently formed wind slabs may remain reactive to human triggering at upper elevations.
Wind slabs have the potential to step down to buried weak layers, resulting in larger-than-expected avalanches.
In the Invermere area, weak faceted snow at the base of the snowpack remains a concern. Avalanches have occurred on steep, smooth north-facing slopes where the snowpack is shallow and weak.
After the storm on Wednesday, numerous natural storm and wind slab avalanches were observed throughout the region (size 1-2) that likely ran during the storm.
On Thursday, explosive control in the Invermere area produced two size 2 deep slab avalanches from east-facing treeline terrain.
Up to 20 cm of recent snowfall accompanied by southwest winds created wind slabs and scoured surfaces at alpine and treeline elevations.
The mid-snowpack may hold a weak layer of surface hoar or facets on shaded slopes and a sun crust on south-facing slopes, buried 20–40 cm deep.
Near Invermere, the snowpack base is weak, with faceted snow over an October crust. This layer likely exists region-wide but has only shown signs of instability near Invermere.
Friday Night
Cloudy with up to 1 cm of new snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Saturday
A mix of sun and cloud with isolated flurries. 5 to 25 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Sunday
A mix of sun and cloud with isolated flurries. 10 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Monday
Cloudy with up to 2 cm of new snow. 10 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
