Snowfall amounts are uncertain for Sunday. If the new snow amounts are upwards of 20cm in your area actual danger ratings may be HIGH
Confidence
Fair - Forecast snowfall amounts are uncertain on Sunday
Weather Forecast
Sunday: Moderate to locally heavy snowfall / Strong southwest winds / Freezing level at about 1000mMonday: Light snowfall / Light west winds / Freezing level at valley bottomTuesday: Clear skies / Light north winds / Alpine temperatures of about -17.0
Avalanche Summary
No reports of recent avalanche activity have been received. I would expect a new round of storm slab activity with weather forecast for the weekend.
Snowpack Summary
Total snowpack depths range from 110 to 160cm at treeline across the region. On the surface a developing storm slab covers a variety of old surfaces which include: old wind slabs at higher elevations, melt-freeze crusts on previously sun-exposed slopes and surface hoar in sheltered terrain.In the mid snowpack you may find a layer of surface hoar buried in mid-November ranging from 60cm-100cm in depth. An October crust/facet combo exists near the base of the snowpack. The most likely place you'd trigger this layer is on smooth, planar, high north facing slopes, especially if the snowpack is unusually shallow in that area.These persistent layers are slowly becoming more difficult to trigger. However, they have the potential to cause large and destructive avalanches, and may 'wake-up' with the increased load of new snow forecast for the next few days.
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.