Buried wind slabs are lurking under our new snow. Avoid steep convex unsupported terrain, limit your exposure to overhead hazards.
Weather Forecast
A dirty ridge of high pressure is moving over us today with a mixed bag of weather. Expect clouds, sun, flurries and light winds. FL staying below the pass today with alp temps hovering around -8c.
Snowpack Summary
Between 50 and 100cm of storm snow now overlies the Nov 13th Crust. Previous strong winds from the Southerly quarter have created wind slabs and cornices. Wind slabs could be hiding under more recently fallen snow and there is a temp/sun crust lurking around 30cm deep on solar asp, but spotty in distribution.
Avalanche Summary
In the Highway corridor on the N asp of Mt Mcdonald we had several avalanches yesterday, mostly size 2 and one size 3. From the backcountry we observed small thin (5cm deep) slab avalanches on N asp and loose dry to size 1.5 running far. The same was observed on Ursus Minor area, and numerous avalanches heard off steep terrain on Mt Cheops
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.