Regions
Northwest Inland.
Strong outflow winds are driving the avalanche danger now that the storm has ended. Seek out supported slopes in wind-sheltered terrain for the safest and best skiing and riding.
Weather Forecast
Saturday: Mainly sunny. Moderate to strong east winds. Alpine high temperatures of -16.Sunday: Mainly sunny. Light variable winds. Alpine high temperatures of -9. Cooler at lower elevations due to a temperature inversion.Monday: A mix of sun and cloud. Light west winds. Alpine high temperatures of -12.
Avalanche Summary
Storm snow and moderate to strong winds have grown cornices and formed widespread wind slabs in the alpine and at treeline elevations.On Wednesday there were reports of numerous natural wind slab and cornice releases up to size 3 triggered by rapid wind-loading. These reports were on predominantly north through east aspects above 1800 m. There were also reports of skier triggered avalanches up to size 2, including a close call north of Kispiox where the 4th skier on the slope triggered a buried wind slab on an east aspect at 1450 m.Tuesday there were reports from northern parts of the region of loose dry storm snow releases up to size 1.5 in steep terrain as well as a skier triggered storm slab (size 1) on steep, southeast-facing, roll that failed on a buried sun crust.On Monday there was a report of a natural size 2 storm slab release on a east aspect below treeline feature that failed on facets buried by recent storm snow. Skiers also reported triggering small storm slab releases on steep convex rolls below treeline.
Snowpack Summary
Moderate to strong outflow winds have been redistributing 50-70 cm of new and recent storm in exposed areas. This storm snow has buried old, hard wind slabs and scoured surfaces in exposed areas as well as sun crusts or dry facets in sheltered terrain.A crust/surface hoar layer buried mid-January is now roughly 80-140 cm below the surface, and still has the potential to be triggered from a thin snowpack spot, or with a large trigger like cornice fall.Facets at the base of the snowpack could also possibly be triggered from shallow snowpack areas.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.