Regions
Northwest Coastal.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Wednesday: Strong S wind, becoming light SW. Alpine temperature near -5. Moderate snow.Thursday:Strong S to SW winds. Alpine temperature near -5. Light snow, becoming moderate late in the day.Friday: Strong SW winds. Alpine temperature near -5. Moderate to heavy snow.
Avalanche Summary
A few wind slabs (size 1.5-2.5) have been triggered naturally and by a machine over the last few days. In one case, a steep wind-loaded SE-facing slope failed as a size 2.5 slab which stepped down to basal facets in the north of the region.
Snowpack Summary
The current medley of snow surfaces includes hard and soft wind slabs, scoured slopes, blue ice, thin melt-freeze crusts and surface hoar. New snow may bond poorly to some of these surfaces, especially where surface hoar sits on a hard crust. Two persistent weaknesses (comprising surface hoar and facets) buried in the upper snowpack give moderate to hard, sudden results in snowpack tests in some locations. The mid and lower snowpack is generally well settled and strong, although basal facets remain a concern in the north of the region.
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.