Use extra caution on wind-loaded terrain features where a slab has formed over a crust. Evaluate snow and terrain carefully before entering high-consequence slopes
Recent winds may have varied in direction so watch for slabs on all aspects. Wind slabs may be more reactive where they overlie weak facets on a hard crust.
On Tuesday, our field team noted a natural size 2 slab avalanche on a north aspect at 1300m. (See photo below). The slab was 20-30 cm deep and failed on facets above a crust, which is the weak layer described in the snowpack summary below.
Reports have been limited, if you head out in the mountains, please consider sharing your observations on the Mountain Information Network.
The primary layer of concern is a layer of weak, facetted, snow that overlies a crust. In most areas, it is buried 20 to 30 cm deep, and extends up to 1750 m. Wind slabs are expected to be more reactive where they have formed over this weak layer.
Further inland regions such as Powder Valley and Mt.Tutshi have less snow, and may also have a weak layer of surface hoar on this crust.
Despite the presence of faceted grains in the lower snowpack, there are no current layers of concern below the crust.
Snowpack depths range from about 70 to 180 cm.
Wednesday Night
Clear. 10 to 20 km/h east ridgetop winds. Inversion; valley bottom -15 °C, alpine -10 °C
Thursday
Sunny. 15 to 20 km/h ridgetop south winds. Inversion; valley bottom temperature -20 °C, alpine -12°C,
Friday
A mix of sun and cloud. 20 km/h southwest ridgetop wind. Treeline temperature -25 °C.
Saturday
Mostly cloudy, with 0 to 2 cm of snow. 30 to 40 km/h south ridgetop winds. Treeline temperature -25 °C.
More details can be found in the Mountain Weather Forecast.
