Recently formed storm slabs may still be reactive to human triggers. Use additional caution in shallow, rocky, or wind affected alpine terrain.
Confidence
Low - Due to the number of field observations
Weather Forecast
Tuesday: Mix of sun and cloud / light southerly winds / Freezing level around 700m. Wednesday: Possible flurries / Light westerly winds / Freezing level around 1000m. Thursday: Mix of sun and cloud / Light northwesterly winds / Freezing level around 800m.
Avalanche Summary
No new avalanches were reported on Sunday. However, on Saturday, numerous size 1-1.5 skier-triggered avalanches at treeline and several size 2-3 natural avalanches in the alpine were reported.
Snowpack Summary
50-80 cm of snow has fallen in the past week with significant winds in the alpine. This has formed storm and wind slabs that have been very reactive to human triggers. These slabs will likely become less reactive in the coming days but will still require careful slope by slope evaluation. The mid-November crust is now buried 60-120 cm deep. Recent reports suggest the overlying snow is well bonded to this crust. Below the crust the snowpack is generally well settled. Snowpack depths vary greatly throughout the region with an average of 130-200 cm at treeline elevations.
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.
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.