Regions
Northwest Inland.
Wind slabs are likely to be encountered at upper elevations and may be reactive to human triggering.
Confidence
Low - Due to the number of field observations
Weather Forecast
TUESDAY NIGHT - Flurries, 5 cm / southeast winds, 20-40 km/h / alpine low temperature near -14WEDNESDAY - Cloudy with flurries, up to 5 cm / southeast winds, 20-40 km/h / alpine high temperature near -8 THURSDAY - Periods of snow, 5-10 cm / southwest winds, 30-60 km/h / alpine high temperature near -1 FRIDAY - Periods of snow, 10-15 cm / south winds, 40-80 km/h / alpine high temperature near +1 / freezing level 1200 m
Avalanche Summary
A natural avalanche cycle to size 2 was reported in the region on Sunday night due to strong to extreme winds in some parts of the region.
Snowpack Summary
10-15 cm of new snow sits above previous wind-scoured surfaces as well as wind slabs in lee terrain features. Below treeline, expect to find a melt-freeze crust near the snow surface.A few buried weak layers that consist of surface hoar (feathery crystals) and/or faceted (sugary) snow may exist in some sheltered areas. The upper layer was buried around December 31 and is about 20-30 cm deep. The next layer may have been buried around December 22 and is likely 40-60 cm deep. The lower one was buried in early December and is now approximately 80-120 cm deep. The bottom 30 to 50 cm of the snowpack consists of facets and crusts, particularly in areas where the snowpack is thin. It is possible that wind slab avalanches could scrub down to ground in thin snowpack areas, resulting in large, full depth 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.