Regions
Northwest Coastal.
Watch for changing conditions with elevation and expect wind slabs on a variety of aspects.
Confidence
Moderate - Wind speed and direction is uncertain
Weather Forecast
SUNDAY: Mix of sun and cloud, light southeast wind, alpine temperatures around -6 C.MONDAY: Cloudy, light southeast wind, alpine temperatures around -4 C.TUESDAY: Isolated flurries with up to 5 cm towards the coast, light southeast wind, alpine temperatures around -4 C.
Avalanche Summary
On Friday, several small skier triggered slabs (size 1-1.5) were reported on a variety of aspects around 1500 m, including a few that were triggered remotely. More evidence of natural avalanche activity during last week's storm was also reported (up to size 3.5).Storm slabs are becoming less reactive with cooling temperatures, but triggering wind slabs remains a concern in exposed terrain.
Snowpack Summary
Outflow winds are forming wind slabs on a variety of aspect in exposed terrain. A total of 15-25 cm of recent snow sits above a rain crust and moist settling storm snow. The February 10th interface is now buried 60-80 cm deep and consists of facets, sun crusts on steep solar aspects, and surface hoar in sheltered locations. This interface is gaining strength, but may still be reactive in isolated areas at treeline where the surface hoar has been well-preserved. Below this layer, the snowpack is generally strong and well settled. The exceptions are shallow snowpack areas around Bear Pass and Ningunsaw where basal facets remain an ongoing concern.
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.