Wind slabs and storm slabs at Treeline and above are sensitive to human triggering. Cautious route-finding advised. Keep an eye on freezing levels as warmer temperatures will lead to an increase in danger level.
Confidence
Fair - Freezing levels are uncertain
Weather Forecast
A mix of sun and cloud expected on Tuesday with freezing levels near 1900m. Very light flurries are possible with light to moderate westerly winds. Alpine temperatures should reach -3 celsius. Slightly snowier conditions expected Wednesday before a warming trend on Thursday and Friday pushes the freezing levels up to 2200m.
Avalanche Summary
No new natural avalanches observed today, but visibility was quite limited. Ski cutting produces small slabs in steep terrain at Treeline.
Snowpack Summary
2cm of new snow through the day with very little wind. Temperatures at treeline rose to above freezing by early afternoon. The snowpack is settling rapidly and the surface snow is moist below 2000m on all aspects but this condition reaches higher on solar aspects. Recent storm snow of up to 60cm is bonding well below treeline, but not as well at treeline and above where moderate shears persist at the January 31st interface. Also at treeline and above new wind slabs have formed in recent days which are reactive to ski cutting. Cornices have experienced significant growth in recent days and several large avalanches have been triggered by cornice failures.
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.