Watch for wind slabs in terrain features near ridges. Also be cautious of your overhead exposure, as cornice falls could trigger slab avalanches.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
SUNDAY: Cloudy with light snowfall, accumulation 2 to 5 cm with possible localized higher amounts from convective flurries, light to moderate southwesterly winds, alpine temperature -6 C, freezing level 1000 m.MONDAY: Cloudy with snowfall, accumulation 10 to 15 cm, light northeasterly winds, alpine temperature -12 C, freezing level 700 m.TUESDAY: Partly cloudy with light snowfall, light westerly winds, alpine temperature -6 C, freezing level 1000 m.
Avalanche Summary
On Friday, loose avalanches were reported from steep alpine terrain on easterly aspects. One small slab avalanche was triggered by a cornice fall, also in steep alpine terrain.
Snowpack Summary
Wind slabs may exist on all aspects at higher elevations from recent snowfall and variable wind directions. Expect to find a melt-freeze crust on the surface on sunny aspects and all aspects below 1700 m. A surface hoar and crust layer is found around treeline at a depth of about 60 cm, with surface hoar on northerly aspects and the crust elsewhere. At ridgetop, cornices are large and have been failing the past few days.Deeper in the snowpack, the late-November weak layer is composed of sugary facets around a crust, which is buried around 200 to 300 cm and is currently dormant.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.