New snow and wind may form fresh slabs near ridgetop.
Continue to stay aware from overhanging cornices, the most likely trigger for a surprising large avalanche.
Fresh wind slabs may have formed at upper elevations and could be human triggered on steep slopes immediately below ridgetop. Old wind slabs formed a few days ago may still be reactive.
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 Monday as new snow was impacted by solar input.
Wet loose avalanche activity may persist as new snow sees sun for the first time on Tuesday.
Up to 15 cm of new snow has accumulated over various surfaces of wind-affected snow, scoured to a crust, and newly formed melt-freeze crust. New snow amounts are variable across the region.
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.
Monday Night
Clear skies. 20 km/h west ridgetop wind. Treeline temperature -11 °C.
Tuesday
Mix of sun and clouds. 20 km/h southwest ridgetop wind. Treeline temperature -9 °C.
Wednesday
Mix of sun and clouds. 1 to 2 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -6 °C.
Thursday
Mostly cloudy. 4 to 5 cm of snow. 20 km/h east ridgetop wind. Treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
