Isolated wind slabs may be lingering at upper elevations.
Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
Wind slabs have formed over a crust layer and have been slow to bond. These slabs may still linger in shaded terrain and may be possible to human trigger.
Cornices have been described as large and overhanging in the Purcells. Cornice failures are dangerous in their own right, but they could also trigger very large and destructive persistent slabs.
A large (size 3) cornice collapsed naturally on Tuesday near The Bugaboos, as well as one small skier accidental wind slab that occurred below a cornice near Golden.
A thin crust has formed on south-facing terrain from recent solar radiation and overnight refreeze. On shaded aspects, 10 to 15 cm of recent snow overlies wind-affected, consolidated snow.
Below this, 30 to 70 cm of snow overlies a thick crust from the recent atmospheric river, which extends up to at least 2200 m.
Various persistent weak layers may still exist in the top 150 cm of the snowpack and in shallow snowpack areas, depth hoar (large facets) can be found near the bottom of the snowpack. Large triggers, like falling cornices, may be able to trigger these layers at upper elevations where the crust below the recent snow is thin or absent.
Wednesday Night
Mostly cloudy. 1 cm of snow. 20 km/h southeast ridgetop wind. Treeline temperature -4 °C.
Thursday
Mostly cloudy. Up to 5 cm of snow. 10 km/h north ridgetop wind. Treeline temperature -3 °C.
Friday
Mostly cloudy. 1 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -3 °C.
Saturday
Mix of sun and clouds. 3 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
