Uncertainty about buried weak layers warrants conservative terrain choices.
A layer of surface hoar is buried 20 to 50 cm deep. If triggered, avalanches on this layer could step down to deeper weak layers.
A layer of weak facets near the ground may be reactive to human triggering, especially in shallow rocky alpine terrain where it is not covered by a thick crust.
Deep persistent slab avalanches (size 1.5 to 2) have been continually triggered with explosive control over the past week, with the most recent occurrence on Monday. On Sunday, a skier in the Dogtooth Range was uninjured after accidentally triggering a size 2 deep persistent slab on basal facets over a smooth rock slab.
New snow is (very) gradually accumulating over surface hoar, facets, and crusts. Beneath lies a thin and complex snowpack with several layers of concern:
A layer of surface hoar buried 20 to 50 cm deep is a concern in areas where it is not covered by a thick crust.
Weak basal facets near the bottom of the snowpack, especially in alpine terrain.
Read this blog post for more details.
Snowpack depths at treeline range from 50 to 130 cm.
Thursday night
Mostly cloudy with a trace of snow, alpine wind southwest 20 km/h, treeline temperature -10 °C.
Friday
Mostly cloudy, alpine wind west 20 km/h, treeline temperature -6 °C.
Saturday
Cloudy with 3 to 8 cm of snow, alpine wind southwest 10 km/h, treeline temperature -6 °C.
Sunday
Sunny, alpine wind southwest 15 km/h, treeline temperature -10 °C.
More details can be found in the Mountain Weather Forecast.
