Regions
Northwest Coastal.
Confidence
Fair - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
Moderate snowfall should start late Wednesday evening and continue until Thursday afternoon. Snowfall amounts are expected to be 15-20cm. Trace amounts are expected on Friday and mostly clear skies are forecast for Saturday. Winds should be moderate to strong from the southwest on Thursday and Friday, switching to light and northerly by Saturday. Freezing levels should be at about 700m for Thursday, 800m for Friday and 500m for Saturday.
Avalanche Summary
No new avalanches to report.
Snowpack Summary
A strong melt freeze crust exists below 1000m on all aspects. On shaded alpine features the surface is mostly wind pressed powder. Variable winds have redistributed 5-10cm of new snow into isolated pockets of wind slab on a variety of aspects in the alpine, although the reactivity of these windslabs has been most recently described as stubborn. The aforementioned new snow may overly buried a surface hoar layer (crystal size reported to be 1-4 mm) at treeline and below. This surface hoar layer seems most prevalent in protected inland areas. Deeper within the snowpack, a facet layer buried around Jan 20th is the greatest concern although triggering seems unlikely. This layer lies approximately 110-140 cm below the surface and still exhibits hard, sudden planar results in isolated snowpack tests.
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.