Continue to travel conservatively especially in the low alpine and around treeline areas. A firm slab, sitting over several persistent weak layers, is found throughout the forecast region and remains a high consequence concern for human triggering.
Weather Forecast
A series of minor disturbances tracking across the region in a NW'ly pattern will bring some continued warming through Sunday. Small amounts of precip and the promise of increased westerly winds this weekend. Similar weather in the outlook for next week after this weekend's disturbance passes...
Snowpack Summary
Previous Strong winds from W and N directions have left wind slabs and wind effect in open areas. The upper snowpack has settled to form a cohesive stiff slab that is sitting on three persistent weak layers mid-pack (down 50 to 80cm) which can be found throughout the forecast region, and have produced many large avalanches that have run full path.
Avalanche Summary
Minimal evidence of recent activity exists: mainly small windslabs in the S and W facing alpine. Widespread wind effect is evident. An extensive cycle was seen as the persistent slab became overloaded with successive storms. Avalanches to sz 3.5 were observed from most aspects and most elevations with the majority of the action seen around 21-2500m
Confidence
Intensity of incoming weather systems is uncertain on Sunday
Problems
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.
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.