Conservative decision making is still required given our present avalanches problems.
Weather Forecast
Conditions will stay cloudy today with isolated flurries bringing trace amounts of precipitation. Expect an alpine high of -2 and westerly winds in the light to moderate range. A ridge of high pressure will begin to dominate the weather pattern for the next several days, although it will remain mostly cloudy until Tuesday.
Snowpack Summary
A sun crust up to 2cm thick is present on steep solar aspects. Recent storm snow has settled to a 45cm soft slab. The storm slab bond to old snow is strengthening, but planar failures are present in stability tests. The December 17th surface hoar on crust layer is down 80-100cm. This layer remains reactive to skier loads on unsupported features.
Avalanche Summary
Natural activity has tapered off since the storm the last storm cycle. A skier controlled avalanche size 1.5 occurred on Thursday on the December 17th surface hoar layer, buried down 60-80cm. This layer has been most reactive around treeline.
Confidence
Due to the number and quality of field observations
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.
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.