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.
No new avalanches were reported but we suspect a loose avalanche cycle occurred on Tuesday as new snow was impacted by solar input.
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.
Tuesday Night
Clear skies. 20 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Wednesday
Mix of sun and clouds. 2 to 3 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -6 °C.
Thursday
Mostly cloudy. 2 to 5 cm of snow. 20 km/h east ridgetop wind. Treeline temperature -3 °C.
Friday
Mix of sun and clouds. 1 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
