Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Tuesday: Light snow. Light W winds. Alpine temperature near -6. Wednesday: 25-35 cm snow. Strong to extreme SW winds. Alpine temperature near -3.Thursday: Light snow. Light SW wind. Alpine temperature near -4.
Avalanche Summary
An avalanche cycle of slabs up to size 3 occurred during the weekend’s storm. Many of these events were on NE-NW aspects above about 2400 m. A few skier-remote triggered slabs were also reported on Sunday. These either failed on a storm snow weakness, or on surface hoar buried below the storm snow. On sun-warmed and low elevation slopes, loose snow and glide avalanches continue to be reported.
Snowpack Summary
Recent storm snow (up to 50 cm in the far south) is sitting on a variable interface, consisting of a crust or moist snow; or a recently formed layer of surface hoar or facets, which is mainly found on high-elevation northerly aspects. In some locations the surface hoar/facet interface is touchy, with skier triggering likely. Winds have shifted storm snow into reactive slabs lee to south-easterly to south-westerly winds. Below treeline, the snow is in a spring melt-freeze regime, melting by day and freezing by night. Cornices are very large and loom as potential triggers for avalanches.
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.
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.