Avalanche Forecast

High

Evidence of a natural loose wet and glide slab avalanche cycle that occurred on Wednesday continues to be reported. These avalanches were triggered by above 0°C temperatures and solar radiation.

On Tuesday, a size 1.5 skier-triggered wind slab avalanche was reported on a north aspect at 1900 m. The slab released on a weak layer of surface hoar below. This layer of surface hoar is spotty but may still be preserved in sheltered areas at treeline and in the subalpine.

A few centimeters of snow cover a melt-freeze crust on solar aspects at all elevations, and up to 1900 m on northerly aspects. In the alpine and exposed treeline, this crust overlies old wind slabs and variable wind-affected surfaces. On sheltered north facing slopes above 1900 m, snow remains dry.

A weak layer of surface hoar or facets is found 10 to 25 cm deep. This layer is a concern where wind slabs have formed above it.

A crust is buried 60 to 100 cm deep and may have a layer of surface hoar sitting above it. Recent tests show this layer as unreactive.

The remainder of the mid and lower snowpack is well-settled.

Snow depths at treeline are roughly 100 to 150 cm.

Thursday Night

Partly cloudy. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -8 °C. Freezing levels drop to the valley bottom.

Friday

Mainly sunny. 10 to 20 km/h north ridgetop wind. Treeline temperature -9 °C.

Saturday

Partly cloudy. 5 to 10 km/h north ridgetop wind. Treeline temperature -12 °C.

Sunday

Partly cloudy. 10 to 20 km/h north ridgetop wind. Treeline temperature -11 °C.

More details can be found in the Mountain Weather Forecast.

• Wind slabs are isolated, but may remain reactive.
• Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.
• A hard crust on the snow surface will help strengthen the snowpack, but may cause tough travel conditions.
• If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.