Skiing has improved and warm temps are helping settle the snowpack. More snow, winds and a rise in freezing level are forecast for Sunday. Avalanche danger will increase with these changing conditions so use conservative terrain choices.
Weather Forecast
Isolated flurries are forecast for Fri and Sat with the freezing level around the 1700m mark. Another system is forecast to arrive on Sun that could bring another 10-15cm with the freezing level rising to 2000m. Winds will increase from moderate on Fri to strong, gusting over 100km/hr Sun.
Snowpack Summary
Rain to 1800m yesterday with cold air moving in from valley bottom. 35-55cm now sits on a buried crust on solar aspects and isolated windslabs found at treeline and above. Between 70 and 150cm now buries the weak February facet layer. Large avalanches will result if this layer is triggered given the demonstrated ability of this slab to propagate.
Avalanche Summary
A loose wet avalanche occurred on Wednesday during the rain event. Numerous sz 2 avalanches have been reported in this weeks storm snow in the surrounding areas. Rapid loading from the forecast wind and snow on Sunday along with freezing level forecast to reach 2000m may result in significant avalanche activity.
Confidence
Intensity of incoming weather systems is uncertain
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.
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.