Weather Forecast
We are in the lull between pulses of moisture. The next pulse, starting sometime this afternoon, should bring us another 20-30cm snow by mid day tomorrow. The avalanche danger will be increasing as the day progresses due to the incoming precipitation.
Snowpack Summary
52cm of storm snow have fallen in the last 24-36hrs accompanied by moderate to strong S through SW wind and warm temperatures. Backcountry travelers should expect freshly formed soft slabs on alpine lees. The storm slab rests on the touchy Nov 11th surface hoar layer. Expect human triggering on this layer given the right terrain.
Avalanche Summary
Field staff watched tree bombs trigger 2 size 1 slabs on the Nov 11 layer Friday. These slides were 25m wide and 50cm deep. Skiers were reporting whumphing and cracking on their tours. This morning there is a lull in precipitation until the next pulse hits this afternoon. Expect increasing avalanche danger as the day progresses.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.
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.