Today's warm storm will overload the Dec 2 weak layer. An avalanche cycle is highly likely. The ski hill will be a better place to head today.
Weather Forecast
The warm, wet storm has arrived and it is bringing upwards of 35cm of snow. Freezing levels will rise, spiking mid-day between 1500-2000m. Strong W winds will accompany the storm. A smaller pulse is expected for Wednesday, to add one more punch to the snowpack.
Snowpack Summary
The widespread Dec 2 surface hoar layer is down 30-65cm and is reactive to human loading. Early November surface hoar layers were also reactive in snowpack tests yesterday, popping off with heavy loads. These test results suggest with a heavy enough load, avalanches could step-down and become much larger.
Avalanche Summary
A natural cycle is underway, with numerous size 2 to size 3 avalanches observed along the highway corridor last night and this morning. Yesterday, field teams were able to easily ski-cut size 1 soft slabs from unsupported features, especially below 1700m
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.