Heads up!! Conditions are ripe even though we are not seeing a lot of natural activity. Stick to sheltered low angle slopes.
Weather Forecast
Seasonable temps into Monday with 10 cm of snow overnight. SW winds predicted to be light. Temps cooling on Tuesday and a bit more snow expected on Wednesday. Max freezing level 1500 m for the next few days with mostly cloudy skies.
Snowpack Summary
Recent sun has developed a weak crust on S through W aspects. Dry, facetted and generally unsupportive facets below this crust. Wind slab on lee aspects from previous SW winds and persistent slab in open areas at tree line. Poor travel conditions below tree line due to weak facetted snowpack.
Avalanche Summary
Size 3 skier triggered avalanche on a SW facing alpine slope up Portal Creek today indicates that the persistent slab can be triggered.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Monday
Problems
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.
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.