Confidence
Fair - Wind effect is extremely variable
Weather Forecast
Cold and mostly clear skies are expected for the forecast period as a dry arctic air mass becomes firmly embedded over British Columbia. Ridgetop temperatures are expected to hover around -14 on Wednesday and Thursday, and then drop to about -20 on Friday. Expect periods of moderate north/northeasterly winds.
Avalanche Summary
Avalanche control in the region produced soft slabs to size 1.5 at higher elevations which formed in response to snowfall and wind on Sunday night. A skier-triggered size1 windslab was also reported close to Mt Brew in the Callaghan area. I would suspect ongoing windslab activity with the current wind speed and direction.
Snowpack Summary
Snow depths are highly variable throughout the region although reports suggest there is an average of about 120cm of snow at upper treeline elevations. Terrain below treeline is reported to be mostly below threshold for avalanche activity.The 25-45cm of snow that fell on the weekend is likely bonding well to old surfaces, but has been redistributed by strong northerly winds. This reverse loading pattern has created new windslabs on south-facing terrain.A few crusts can be found deeper in the snowpack which may have associated facets at higher elevations. Observers are not identifying any of these as cause for concern at this time, although they might be worth exploring.
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.