Natural avalanche activity has largely subsided, but the potential for human-triggering remains. Due to the weak basal structure of the snowpack, very large avalanches are possible. Conservative route selection is advised.
Weather Forecast
The next few days will be cool (highs near -15 °C) with light flurries. Snow accumulations are not expected to be significant. Winds will be moderate from the West on Saturday and then switch to light from the East on Sunday.
Avalanche Summary
Nothing new today, but some large naturally triggered avalanches have occurred over the past week.
Snowpack Summary
Recent storm snow has settled to an average of 20cm deep, with very little wind effect in most areas below 2500m. On steep solar aspects there is a buried suncrust (Feb 17th layer) down 20-30cm. Beneath this, the upper snowpack remains well settled with denser slabs as the 50cm depth is reached. The basal layers are alive and well and vary between 30-50cm thick, and is a dog's breakfast of crusts, facets and depth hoar. Snowpack stability tests today indicate a sudden collapse failure within the basal layers in the moderate range. These tests were done in a slightly shallower morainal feature, and indicate the possibility of full-depth avalanches if the "sweet spot " is triggered.
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.
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.