Sea To Sky

Strong northerly, outflow winds have scoured windward slopes and created hard wind slabs on lee slopes at upper elevations. Watch for areas of "pillowy" or hollow, drum-like sounding snow.

Moderate - Forecast snowfall amounts are uncertain on Sunday

SATURDAY: Sunny. Ridge wind light from the northeast. Temperature -9. Freezing level surface.SUNDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind light from the southeast. Temperature -8. Freezing level surface. Strong outflow winds near coastal valleys.MONDAY: Mix of sun and cloud, light flurries. Accumulation trace. Ridge wind light from the northwest. Temperature -6. Freezing level surface.

On Thursday there was a report of a small (size 1) skier accidental wind slab release on a north aspect in the alpine. On Wednesday, several small, skier-triggered avalanches were reported as well as explosives triggered slab avalanches up to Size 3 on wind-loaded slopes in the alpine and at treeline. See here and here for recent Mountain Information Network (MIN) reports.And earlier in the week, numerous natural, skier controlled and skier remote storm slab avalanches to Size 2 were reported on various aspects and all elevations running both within the storm snow as well as on the Dec 15th melt-freeze crust. See here for details. 

The recent storm snow has been redistributed by strong northerly winds building wind slabs on lee aspects and scouring windward aspects in the alpine and exposed treeline areas. This has created a highly variable upper snowpack depending on aspect and elevation with areas of both soft and hard snow as well as areas of exposed crust. An average of 30-50cm of storm snow now sits on a melt-freeze crust (December 15th layer) that formed on all aspects and elevations. On high north aspects this crust is thin with dry, sugary snow crystals (facets) below. Below the December 15th layer, the late November crust is now buried 70-100 cm with a thin layer of facets above. Beneath this crust the lower snowpack is well settled.