Wind slabs may exist on all aspects following a shift in wind direction. Carefully assess steep slopes for reactive slabs.
Firm, reactive wind slabs could exist at all elevations due to strong, variable winds at higher elevations and cold outflow winds at valey bottoms.
Widespread natural wind slab avalanche activity has been reported since Monday. These have primarily occurred in treeline and alpine terrain, on a variety of aspects.
Moving forward, we expect natural avalanche activity to decrease as winds ease and loose snow becomes less available for transport. However, human-triggered avalanches will remain possible.
Be sure to post your observations to the MIN if you get out!
Snow surfaces have been heavily wind-affected in the alpine and in exposed terrain at treeline and below. Windward slopes are scoured down to old crusts or sastrugi, while leeward slopes have been heavily loaded, forming firm wind slabs that may be sitting atop a crust with weak faceted snow or surface hoar above.
In isolated, wind-sheltered terrain, 20 to 60 cm of snow may sit atop a crust and/or surface hoar, primarily at treeline and below.
A January crust with associated facets is buried roughly 100 to 200 cm below the surface. Below, the remainder of the snowpack is generally well settled and well bonded.
Wednesday Night
Clear skies. 30 km/h northwest ridgetop wind. Treeline temperature -17 °C.
Thursday
Mostly sunny. 30 km/h west ridgetop wind. Treeline temperature -14 °C.
Friday
Mostly cloudy. 2 to 3 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -13 °C.
Saturday
Mostly cloudy. 1 to 5 cm of snow. 50 km/h southeast ridgetop wind. Treeline temperature -11 °C.
More details can be found in the Mountain Weather Forecast.
