Lots of snow available for transport. If the winds pick up, watch for touchy windslabs developing in lee areas.
Weather Forecast
Mainly cloudy with scattered flurries today. Winds will pick up to moderate values from the SW. Temperatures are continuing to rise, but freezing levels will remain at valley bottom for at least another day.
Snowpack Summary
25-30cm of storm snow sits over the December 8 surface hoar layer at lower elevations and over variable wind slabs up high. The storm snow is mainly low density with some soft slab developing in the alpine. The November 28 surface hoar layer is down around 35-40cm over a facetted mid-lower snowpack. The Nov 12 surface hoar layer is down 60-110cm.
Avalanche Summary
A couple of size 1.5-2.5 slab avalanches were observed from the steep start zones off Mt MacDonald and Cougar Corner yesterday. Sluffing of the low density surface snow was observed in unsupported terrain, steeper than 35 degrees.
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
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.