Avoid backcountry travel for the time being. Recent avalanches have gone further than expected. In some case, mature trees have been taken down. A great time for the groomed XC ski trails or resorts!
Weather Forecast
Tonight will see another storm arrive from the SW. This will be with us for a day and bring significant amounts of snow. The main pulse is expected tomorrow and will leave just over 30cm. With the snow, we'll also see strong to extreme winds. At 2500m we're expecting SW winds 55-65km/hr. The temperatures will also creep up to -1° at 2500m.
Avalanche Summary
Nothing new was seen today, however clear skies offered a view of the extent of the last cycle. Alpine & treeline elevations had numerous avalanches on all aspects. All of them involved the deep layers. In terms of size, 2.5 to 3.5 avalanches were common. Crowns were up to 1.5m deep with very wide propagations.
Snowpack Summary
No new snow has fallen in the region today. The winds however have been moderate to strong in the alpine and have helped to build the windslabs. The re-distribution has caused localized loading in lee areas. An already stressed snowpack is struggling to support the new load. The cooler temps and cloud cover today helped to minimize the sun's effect and keep the surface snow cool. The principle concern at all elevations and aspects is still the deep, basal weak layers. The windslabs are a problem in themselves, but the bigger issue is the slabs' ability to trigger the deeper layers. Cornices are another large trigger that will almost certainly initiate a deep avalanche.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.