Regions
Northwest Coastal.
Winds have created a variable snowpack. Be alert to conditions that change with aspect and elevation.
Confidence
Fair - Intensity of incoming weather systems is uncertain
Weather Forecast
Generally light precipitation is expected on Wednesday and Thursday, with the freezing level around 1200 m and winds moderate to strong from the S to SE. On Friday, a more organised system brings 5-15 mm precipitation with the freezing level near 1400 m.
Avalanche Summary
On Monday, several loose avalanches to size 1.5 were observed on solar aspects. A skier triggered a size 1 wind slab in the alpine. Explosives control on Sunday triggered several very large avalanches near Stewart, failing at ground or on a deeply buried crust.
Snowpack Summary
Around 1 m of recent storm snow was redistributed by strong and variable winds, creating widespread wind slabs. Operators now report reasonable settlement and bonding within the storm snow. Older buried surfaces include wind slabs, hard crusts, surface hoar, and/or surface facets. The mid-pack is generally well-settled and strong. At the base of the snowpack, weak facets may be found, particularly on shallow alpine slopes in the north of the region. Cornices are large and potentially fragile. Below treeline, the snow appears to be in a spring melt-freeze cycle.
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.