Touchy conditions are expected, especially at higher elevations. Check out the most recent Forecaster Blog for more details on the current conditions. http://www.avalanche.ca/blogs/VLsBsCgAACYAJdfM/mid-jan-sh
Confidence
Fair - Due to the number of field observations
Weather Forecast
Unsettled conditions and light flurries are expected on Monday as a pacific frontal system exits the region to the southeast. By Tuesday a weak dry ridge of high pressure will rebuild. Confidence in the forecast for Wednesday gets shaky on Wednesday as weather models disagree on the ridge's ability to deflect a system creeping in from the northwest. Stay tuned! On Monday, ridgetop winds are expected to be moderate from the west, dropping to light from the northwest on Tuesday and Wednesday. Freezing levels should hover around 1400m on Monday, and then drop to near valley bottom for Tuesday and Wednesday.
Avalanche Summary
Natural and human-triggered wind slab activity to size 1.5 was observed in response to new snow and wind on Friday night. With more snow and wind on Sunday, I'm sure the developing storm slab has increased in size and reactivity. In sheltered terrain where the new snow is less consolidated, I would expect fairly widespread loose dry avalanche activity in steep terrain. In isolated terrain, a surface avalanche in motion may also "step down" to a deeper, more destructive weak layer which was buried in mid-December.
Snowpack Summary
Up to 35cm of new snow has fallen since Friday night. The new snow, which has been distributed into deeper deposits in higher wind-exposed terrain, overlies widespread 5-15mm surface hoar and a sun crust on steep sun-exposed slopes. The problematic mid-December surface hoar/crust layer is typically down 50-90cm below the surface and continues to produce clean shears at and below treeline. Although less likely to trigger, I'd continue to treat this layer with respect and suspicion as an avalanche at this interface may have nasty consequences.
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.