Avalanche danger ratings are based on light to locally moderate accumulations on Saturday night. If snowfall amounts are higher, the danger rating will increase.
Confidence
Poor - Forecast snowfall amounts are uncertain on Sunday
Weather Forecast
Sunday: Light to locally moderate snowfall on Saturday night should ease to light snowfall by Sunday / Moderate southeast winds / Freezing level at 900mMonday: Mostly clear skies / Light southeast winds / Freezing level at 900mTuesday: moderate snowfall / Light southeast winds / Freezing level at 600mConfidence: Good for the overall pattern / Poor for specific snowfall amounts on Saturday night/ Sunday morning
Avalanche Summary
Explosives control on Friday produced storm/windslab avalanches to size 2. I would suspect ongoing new snow avalanche activity on Sunday if snowfall/winds are moderate or higher.
Snowpack Summary
The region has received an impressive amount of new snow in recent days with over a metre falling throughout the week in some areas. The snowfall was accompanied by consistently strong to extreme winds that have since backed off leaving windslabs at higher elevations and deep loose snow below treeline.A couple of layers of surface hoar were buried last week in some areas. Another deeper layer of surface hoar from late November is now well over a metre down. No activity has been reported on any of these surface hoar layers. In general, the mid-pack is reported to be well settled and strong. The early November crust/facet combination near the base of the snowpack seems to be dormant; however, the consequences of a deep release would be very serious. Avalanches at this interface would most likely require a large trigger along a thin, unsupported snowpack area.
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.