Regions
Northwest Coastal.
The danger is based on 40 cm of snow that is forecast Thursday night. If you find lesser amounts, conservative route-selection is still recommended, as the new snow may not bond well to underlying layers and it may be touchy to human traffic.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
THURSDAY NIGHT: Cloudy with snowfall, accumulation 30 to 40 cm, moderate to strong southwest wind, alpine temperature -6 C, freezing level 500 m.FRIDAY: Cloudy with snowfall, accumulation 5 to 10 cm, light to moderate southwest wind, alpine temperature -5 C, freezing level 700 m.SATURDAY: Early-morning snowfall and clearing over the day, accumulation 5 cm, light east wind, alpine temperature -10 C.SUNDAY: Clear skies, light to moderate east wind, alpine temperature -12 C.
Avalanche Summary
On Wednesday, a few small (size 1.5) wind slab avalanches were triggered by skiers. The slabs were about 20 cm deep. Avalanche activity will likely increase Thursday night into Friday as the storm passes.
Snowpack Summary
The next storm on Thursday night and Friday will add to the recent 15 cm of snow from Tuesday. Around 30 to 40 cm of snow is expected with this storm, and it is falling with strong southwest wind. All of this snow overlies weak faceted snow that may sit above hard surfaces, like wind-pressed snow or a crust.In the south of the region, the remainder of the snowpack is well-settled.Around Bear Pass and in the north of the region, you may find two weak layers of surface hoar buried between 50 and 100 cm. The base of the snowpack may also be composed of weak and sugary faceted snow.
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.