Small pockets of wind slabs can still be triggered on alpine features.
Evaluate slopes on an individual basis before committing to them.
Newer wind slabs have formed in cross-loaded terrain due to reverse loading. Lingering pockets of old wind slabs exist in lee features. Keep approaching convex and unsupported features with caution.
A human-triggered slab occurred at Fissile Peak on a northwest lee slope and ran on a crust layer. Several small (size 1) wind slab avalanches were reported in the last 48 hours. Debris from loose wet avalanches (size 1) was observed on steep alpine south-facing slopes around the Whistler area.
Please keep sharing your observations via the MIN; it helps strengthen our information gathering!
On steep south-facing slopes, a sun crust has developed over the past weekend. On shaded terrain at all elevations, large surface hoar (up to 10 mm) is present, along with unconsolidated snow. The upper snowpack consists of 20-50 cm of light snow, overlying old surfaces such as wind-affected surfaces.
Down 40-60 cm in the snowpack, a thick melt-freeze crust is found up to 2200 meters. Faceting has been observed between the wind slab and the crust. Professionals are concerned about the possibility of wind slabs fracturing at this deeper interface.
The snowpack sits around 70 to 120 cm at the treeline and up to 180 cm in the alpine. Much of the below treeline elevation band is below the threshold for avalanches.
An arctic ridge of high pressure will continue to be the main attraction. Conditions will be dry until the next pulse of snow, expected Wednesday night through Thursday.
Monday Night
Cloudy. No precipitation. Light westerly ridge wind. Low -10 C. Freezing level at valley bottom.
Tuesday
Cloudy. Isolated flurries. 2 cm. Westerly ridge wind gusting 40 km/h. Low -8 C. Freezing level at valley bottom.
Wednesday
Partially cloudy. 5 cm in the afternoon. Southwesterly ridge wind up to 50 km/h. High -5 C. Freezing level around 700 m.
Thursday
Snow 15-20 cm. Southwesterly ridge wind up to 60 km/h. High of -3C at treeline. Freezing level around 800 m.
More details can be found in the Mountain Weather Forecast.
