Regions
Northwest Inland.
Avalanche danger is rising with incoming snow and strong winds.
Confidence
Fair - Due to the number of field observations
Weather Forecast
5-10 cm snow is expected on Thursday. This is followed by cloudy skies with possible flurries on Friday and Saturday. Strong to gale SW to W winds persist over the next three days. The freezing level is near 1000 m.
Avalanche Summary
A skier triggered an isolated size 1 wind slab in the alpine on Tuesday. Small loose moist avalanches were also observed on steep solar aspects over the last couple of days. Over the weekend, avalanches to size 3 were reported from steep un-skiable south through west facing terrain features and isolated cornice fall produced a few slabs out of extreme terrain. Very thin wind slabs on NE facing alpine features were also observed. Glide cracks are starting to open up too. New snow and wind are likely to create storm slabs and wind slabs which could be triggered naturally, or with the weight of a person.
Snowpack Summary
Incoming snow and strong winds are likely to build wind slabs on lee features, and storm slabs in more sheltered spots. Previous outflow winds created isolated stiff thin wind slabs, which may now be buried under new snow. A variety of other interfaces may be found under the new snow, including a sun crust, an old rain crust, surface hoar, and/or surface facets. At the base of the snowpack, weak facets may be found. Keep an eye out for cornices that could fail.
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.
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.