Regions
Northwest Inland.
Pockets of thin wind slab can be found in the alpine and at tree line.
Confidence
Moderate - The weather pattern is stable
Weather Forecast
We're looking at a period of fairly benign weather over Christmas before a powerful storm is forecast to hit the North Coast. There may be some isolated flurries although no significant accumulations of new snow are expected through Friday. An artic front just inland stretches almost all the way down the coast and will keep freezing levels at, or close to valley floor throughout the forecast period. Winds will be light and variable on Thursday before becoming moderate westerlies by Friday. On Saturday everything changes with 5 and 10cm of new snow expected through the day, accompanied by very strong southwesterly winds at ridge top.
Avalanche Summary
No new avalanches have been reported.
Snowpack Summary
A skiff of new snow may be covering thin stiff wind slabs in alpine and above tree-line features on a variety of aspects lee to the variable recent winds. These winds have been mainly out of the northeast in areas under the influence of cold arctic air, and out of the south or southeast when the snowstorms have moved inland from the coast. Below this we're still dealing with a thin, early-season snow pack for much of the Northwest Inland region. Between 80 and 100 cm of snow can be found at tree-line in the south and west of the region, with closer to 60 cm in the east. A layer of surface hoar has been reported to be just below the surface in isolated sheltered areas although it may be hard to find. A weak basal layer probably exists in areas with a shallow snowpack.
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.