Enjoy the holidays and remember to practice with all your new rescue gear!
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Sunday
Weather Forecast
On Sunday, expect up to 10cm of new snow and strong southwest winds. A gradual clearing trend is forecast for Monday and Tuesday as a dry ridge of high pressure develops over the region. Winds associated with the ridge should be generally light and northeasterly. Freezing levels are expected to hover around valley bottom for all 3 days.
Avalanche Summary
No recent avalanches have been reported. With new snow and wind forecast for the weekend, I expect a round of wind slab activity in high elevation lee terrain.
Snowpack Summary
By Sunday afternoon, I expect about 10cm of new snow to have fallen. In exposed, high elevation terrain, strong southwest winds will have shifted these new accumulations into fresh and potentially reactive wind slabs in lee terrain. At lower elevations, you may be able to find either isolated pockets of surface hoar or a crust with facets that was reported to be buried on December 17th. Reports from the field indicate that this layer is now starting to break down and gain strength.
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.