Regions
Northwest Coastal.
New wind slabs may build on Thursday. Use extra caution in wind-loaded terrain. Are you a member of Avalanche Canada? Join today at avalanche.ca/membership
Confidence
Fair - Intensity of incoming weather systems is uncertain
Weather Forecast
2-4mm of precipitation is expected Wednesday overnight with light-to-moderate alpine winds from the NW. Another 3-6mm is expected for Thursday. Freezing levels are forecast to reach around 1200m and alpine winds should remain light-to-moderate. On Friday, dry and clear conditions are expected as the ridge will re-establish over the region. Freezing levels are expected to be around 1200m and alpine winds moderate-to-strong from the NE. Saturday is currently forecast to be another day of full sun.
Avalanche Summary
On Tuesday, an explosive-triggered size 1 wind slab avalanche was reported. On Monday, numerous wet releases up to Size 2 were reported from steep sun-exposed slopes. Isolated cornice failures and ice falls have recently been reported. Last week several full-depth avalanches up to Size 3 were observed on all but North aspects. On Thursday, fresh wind slabs are the main concern.
Snowpack Summary
The snow surface is highly variable and may include wind-pressed surfaces or old wind slabs, a sun crust or old rain crust, surface hoar, and/or surface facets. A layer of surface hoar buried in the upper snowpack has been reported in some areas and is worth investigating before committing to any big alpine terrain. At the base of the snowpack, weak facets may persist.
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.