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.
Confidence
Low - Due to the number of field observations
Weather Forecast
High pressure dominates the weather pattern for the next few days. The next major weather maker is not expected in the Cariboos until at least Friday. MONDAY: Trace of snow, freezing level at valley bottom, light W wind at lower and mid elevations, moderate NW wind at ridgetop. TUESDAY: Trace of snow, freezing level at valley bottom, light W wind at lower and mid elevations, moderate NW wind at ridgetop. WEDNESDAY: No snow expected, freezing level at valley bottom, light NW wind at lower and mid elevations, moderate NW wind at ridgetop.
Avalanche Summary
Large natural sluffs to size 1.5 were reported from all aspects between 1300m and 2400m Saturday. The last significant observation was from Thursday when a large natural avalanche (size 2.5) was observed on a NE facing feature at 2000m.
Snowpack Summary
A string of storms between December 2nd and December 13th produced 80 to 150cm of storm snow in the Cariboos which is settling out at all elevations. You may find a brittle thin crust about 15 to 50cm below the snow surface as high as 1800m that was formed by rain and warm temperatures on December 8th. Below all the new snow lies the early December persistent weak layer. This weak layer manifests as an old sun crust on due south facing features in the alpine, large grained surface hoar below 1800m and small facets in isolated pockets. The surface hoar has been the primary concern lately, especially below treeline between 1400m and 1800m. Test profiles have been producing moderate resistant planar results on the surface hoar which suggests that it's becoming less sensitive to human triggering. Recent winds out of the south and southwest have formed wind slabs on lee features that are mainly confined to the alpine, but you may find the odd fresh wind slab at treeline too. The mid and lower portions of the snowpack are thought to be well settled.
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.