Regions
Northwest Coastal.
Be observant of wind effect as you transition to higher elevations. Expect storms slabs to be more reactive in wind affected terrain.
Weather Forecast
Friday: Mainly cloudy. Light east winds. Alpine high temperatures to -3Saturday: Cloudy with scattered flurries bringing 2-5 cm of new snow. Light to moderate southeast winds. Alpine high temperatures to -5.Sunday: Cloudy with isolated flurries and a trace of new snow. Moderate east winds. Alpine high temperatures of -6.
Avalanche Summary
Reports from Thursday showed ski cutting producing loose wet releases to Size 1 in steep terrain in the Shames area. Several older Size 1.5 natural storm slab releases were also noted. Looking forward, the storm slabs that formed over Thursday may remain reactive to human triggering on Friday. This concern will be greatest in wind affected areas at higher elevations.
Snowpack Summary
Snowfall over Wednesday and Thursday brought about 20 cm of new snow to the region. Moderate southwest winds over Thursday promoted storm slab formation at higher elevations and particularly in lee areas subject to wind loading. The new snow has buried a mix of old wind slabs and temperature crusts left over from the weekend. Professionals have been monitoring a few layers in the upper snowpack, including crusts and surface hoar layers buried 40-80 cm below the surface. Although these layers have been reactive in recent snowpack tests, they have not produced avalanches lately. The lower snowpack is generally strong, with the exception of areas around Stewart and further north where a basal crust and facets exist.
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.