Regions
Northwest Coastal.
Variable winds will drive avalanche conditions in the coming days. The best riding conditions can be found in sheltered areas, but be mindful of the layer of surface hoar buried at tree-line
Weather Forecast
Were entering into a period of fairly benign weather. Light snow with accumulations of around 5cm are expected for coastal regions with only isolated flurries forecast inland of Terrace overnight and into Tuesday. Winds look to variable, coming from the west on Tuesday, becoming south easterly on Wednesday, and returning to the west on Thursday. Freezing levels are expected to remain around 500m for coastal regions and at or close to valley bottom for inland regions through the forecast period.
Avalanche Summary
Several small naturals were reported from steep rock slabs at low elevations above the highway. No new avalanche reported from higher elevations although I suspect that travel and visibility may have been restricted by stormy conditions.
Snowpack Summary
The recent storm brought 20 cm of new snow to Shames, with slightly more further west. The north of the region around the east end of the Bear Pass received up to 40cm. Soft storm slabs are developing, especially in wind loaded features, and cornices are forming at ridge-top. The new snow continues to add load to several buried weak layers. There is now 25-40 cm above the December 17th surface hoar, and 35-55 cm above the December 14th surface hoar. The December 1st surface hoar is now down a meter or so depending on your area. The distribution of this layer is variable. In some areas, it may still be sensitive to human triggering and capable of wide propagations. In other areas it is non-existent or has gained significant strength. Conditions may be different close to Kitimat, where it looks like recent snowfall amounts may be a bit higher and temperatures a bit warmer
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.