The danger has come down, but large human triggered avalanches remain possible. Start with small test slopes and build up slowly to the bigger terrain features. There is still a lot of uncertainty associated with this early winter snowpack.
Weather Forecast
A northwest flow will bring light snowfall, and cool temps throughout the forecast period. TUESDAY: 2-5cm new snow, light northwest winds, -5 at 1500m. WEDNESDAY: Flurries bring up to 2cm of snow, light northwest winds. THURSDAY: Overcast, light northwest winds.
Avalanche Summary
Avalanche activity appears to have tapered off since Friday. Reports from the Columbia Mountains over the weekend detail sluffs in steep terrain, natural slab avalanche up to size 2 failing on a mid-storm instability, and skier controlled avalanche on wind loaded features
Snowpack Summary
Between 80 to 150cm of snow fell last week in the Cariboos. You may find a thin crust about 15 to 50cm below the snow surface as high as 1800m. Below the new snow lies the early December persistent weak layer. This layer may be found as either an old sun crust on south facing features in the alpine, or as large surface hoar and/or small facets in isolated pockets below treeline, especially between 1400m and 1800m. Recent test results on this interface have been widely variable. Sudden planar, resistant planar and sudden collapse results have been reported on the surface hoar as recently as December 13th. Recent winds out of the south have formed wind slabs on lee features that are mainly confined to the alpine, but you may find the odd fresh wind slab at tree-line too. The mid and lower portions of the snowpack are thought to be well settled.
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.
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.