Regions
Northwest Inland.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Two frontal systems are due to affect the area, but the timing of these is uncertain.Tuesday: Moderate S wind. Alpine temperature near -1. Light snow.Wednesday: Light to moderate SW wind. Alpine temperature near -6.Moderate snow.Thursday: Increasing S winds. Alpine temperature near -5. Moderate snow, probably starting late in the day.
Avalanche Summary
On Friday, hard wind slabs failed naturally in the north of the region on northeast and east aspects. In isolated occurrences, these triggered full-depth avalanches that ran on basal facets. No avalanches have been reported since then.
Snowpack Summary
The current medley of snow surfaces includes hard and soft wind slabs, scoured slopes, blue ice and thin melt-freeze crusts. Surface hoar layers buried in the upper snowpack are patchy in their distribution. Recent snowpack tests gave moderate to hard, resistant results on one of these layers near Smithers. An otherwise strong mid-pack overlies a weak base layer of facets/depth hoar and the remnants of a crust. The snowpack depth is around 100 cm at treeline.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.