Regions
Northwest Coastal.
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Confidence
Fair - Wind effect is extremely variable
Weather Forecast
Apart from some light snow or flurries on Sunday, the next few days look dry and cool. Winds are moderate to strong from the north quarter (although the direction will vary locally).
Avalanche Summary
On Thursday and Friday, several size 1 skier initiated avalanches were reported. It is expected that these were thin wind slabs. Last week several full-depth avalanches up to size 3 were observed on all but north aspects. If the region gets substantial warming and sun again, isolated events like these could once again become active. Loose sluffs from steep sun exposed slopes are also possible.
Snowpack Summary
Cornices may be sensitive to warm temperatures. Wind slabs may be lurking on slopes lee to outflow winds. These can be triggered by a person, but have been reported to be mainly small. On other slopes, variable surfaces include a sun crust or old rain crust, surface hoar, and/or surface facets. A layer of surface hoar buried in the upper snowpack is worth investigating before committing to any big alpine terrain. At the base of the snowpack, weak facets may be persisting.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.