The stability of recent storm snow will vary across elevation and aspect. Be careful to note changes as you travel. The Dec 17 surface hoar layer continues to produce skier triggered avalanches at treeline
Weather Forecast
Mainly cloudy today with no sign of precipitation. Winds at ridge top will remain light with an alpine high of -1. A weak disturbance is expected to bring trace amounts of snow on Saturday. A high pressure system will return for the early part of next week, bringing dry conditions for the foreseeable future.
Snowpack Summary
A thin sun crust is present on steep solar aspects. Recent storm snow continues to settle and bond to the old snow surface. 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 begun to taper off since the storm, however isolated size 2 avalanches continue to be observed on steep terrain in the highway corridor. Yesterday a field team on Mt Abbott was able initiate a Sc size1.5 on a convex roll near treeline. The failure plane was the Dec 17 surface hoar, which had previously released and reloaded.
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.