Continue to be cautious on large slopes in the alpine, and avoid likely triggering spots like convex rolls and thin snowpack areas. Expect avalanche danger to increase over the next few days; a storm may overload a persistent weak layer down 1 meter.
Weather Forecast
Today is looking mostly cloudy with flurries. It's possible there may be a few sunny breaks in the alpine, with temps of -9'C with light W'ly winds. A storm is expected to hit mid-day on Friday, bringing ~10-15cm of snow with moderate SW winds loading lees. Saturday the storm continues with another ~15cm of snow and moderate to strong winds.
Snowpack Summary
10-20cm of powder overlies settled snow & windslabs in the alpine. The Nov 13 crust is buried ~60 and 100cm deep. In most areas the crust seems to be bonding well but is of most concern on S'ly aspects. Tests on a SW aspect, 2075m indicated that the crust may be triggered by light loads and that it is capable of propagating into a large avalanche.
Avalanche Summary
Natural avalanche activity has been limited to small loose avalanches over the past few days. A field team yesterday ski cut numerous steep unsupported rolls while descending from Lookout Col and found the snow to be unreactive in that area.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.