The likelihood and size of slab avalanches depend on the depth of a recently buried weak layer. Consider the consequences of a potential avalanche when placing yourself in the terrain.
A weak layer of surface hoar on a melt freeze crust is buried an average of 30 cm, but up to 60 cm in wind loaded areas. Both the likelihood of triggering and consequence are greatest in places where it is deepest.
In the warm weather on Thursday, loose wet avalanches were observed on steep solar aspects, average size 1 but up to size 2.
Over the past week and as recently as Thursday, several natural and human-triggered persistent slab avalanches size 1–1.5 have occurred across the region, failing on the late-January layer. Most of these avalanches have occurred near treeline.
A dusting of new snow falls over a thin surface crust or moist snow.
A widespread weak layer is buried 30 to 40 cm deep. It formed in late January and consists of surface hoar on a melt-freeze crust, with facets below. This layer is expected to remain a concern as it becomes buried deeper.
The mid and lower snowpack remain well settled, with no significant concerns at this time.
Friday Night
Mostly clear skies. 30 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 2300 m.
Saturday
Increasing cloud. 4 to 5 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1300 m.
Sunday
Mostly cloudy. 4 to 5 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1700 m.
Monday
Mix of sun and clouds. 1 cm of snow. 20 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level 1700 m.
More details can be found in the Mountain Weather Forecast.
