Regions
South Coast Inland.
Fresh wind slabs have formed throughout the region. In northern parts of the region be cautious around thin rocky areas where wind slabs could step down to deeper weak layers.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
MONDAY: Cloudy with sunny periods, light west winds, alpine temperatures around -4 C in the south and -8 C in the north.TUESDAY: Mix of sun and cloud, light northeast winds, alpine temperatures around -10 C.WEDNESDAY: Sunny, light northeast winds, alpine temperatures around -13 C.
Avalanche Summary
Recent MIN reports do a great job highlighting recent avalanche activity in the region. Wind slabs were very reactive to human triggers over the weekend, releasing numerous size 1-1.5 avalanches on north and east aspects. On Friday, two skiers were caught in a larger wind slab avalanche that carried them down a steep north facing couloir in the Coquihalla area (see MIN report). Wind slabs will likely continue to be reactive to human triggers in the lee of exposed terrain the next few days. In thin rocky areas to the north, wind slabs could potentially step down to deeper weak layers. Thanks to everyone who's shared observations on the MIN!
Snowpack Summary
SOUTHERN AREAS (e.g. Coquihalla): Light flurries have buried a variety of crusts and settled storm snow. Small fresh wind slabs linger on northerly aspects.NORTHERN AREAS (e.g. Duffey Lake): Light flurries with strong southwest winds have formed fresh wind slabs in the lee of exposed terrain. The new snow sits above a thin breakable sun crust and isolated pockets of surface hoar, potentially creating weak interfaces for wind slabs to propagate along. The upper snowpack has 50-80 cm of settled storm snow sitting above the mid-January surface hoar and facet interface. This interface produced large avalanches during the last storm cycle, and may still be poorly bonded in thin snowpack areas such as the South Chilcotins.
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.