Fresh storm and wind slabs will likely take a few days to strengthen.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Expect another 10-20 cm of snow on Thursday falling mainly in the morning and afternoon with freezing levels around 1400 m and moderate to strong southerly ridge top winds associated with the precipitation. After another 15-25 cm overnight, a drying, clearing, and cooling trend is expected to start on Friday with isolated flurries, freezing levels dropping as low as 1000 m and winds easing to light westerlies by the evening. At this point Saturday is looking mostly dry with a mix of sun and cloud, freezing levels below 1000 m and light ride top wind.
Avalanche Summary
Reports from Tuesday include numerous natural wet storm slab avalanches up to Size 2 at treeline and alpine elevations. Several were triggered by cornice collapses.
Snowpack Summary
Fluctuating freezing levels and heavy precipitation has generally resulted in rain-soaked snow that should soon be frozen into a solid crust that extends as high as alpine elevations with 15-20 cm of fresh wet snow stuck on top, depending on elevation. Meanwhile in the high alpine, deep fresh storm and wind slabs have likely developed, and weakness deeper in the snowpack, such as crusts with associated facets, likely remain under critical loads. The snow pack depth drops significantly below treeline with essentially no snow below 1600 m.
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.