Regions
Northwest Coastal.
Confidence
Fair - Timing or intensity of solar radiation is uncertain for the entire period
Weather Forecast
Monday: Sunny. Light winds. Freezing level around 700 m.Tuesday: Sunny. Light winds. Freezing level around 400 m.Wednesday: Sunny. Light winds. Freezing level around 300 m.
Avalanche Summary
Sunshine and warming have triggered loose avalanches over the last couple of days. Isolated pockets of wind slab have been triggered by skiers. A widespread natural cycle occurred in response to snow and wind-loading on Wednesday/Thursday, with several slabs of size 2-3, and a few in the size 3-4 range. The largest event failed as the entire snowpack on basal facets and was triggered by cornice fall.
Snowpack Summary
About 40-70 cm recent storm snow is showing signs of stabilizing. Recent strong, variable winds left wind slabs at treeline and alpine elevations. Direct sun is weakening the snowpack on sunny aspects during the day. A layer of surface hoar, facets and/or a crust is buried in the upper snowpack, but most operators report a good bond at this interface. Some large cornice falls have been reported over the past few days. Most have not triggered slabs on the slopes below, however one triggered a very large avalanche. The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack have resurfaced as a concern now that spring is on the doorstep and full-depth releases are becoming more likely.
Problems
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.
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.