Dangerous avalanche conditions continue. Travel in avalanche terrain is not recommended.
Two surface hoar layers can be found in the top meter of the snowpack in sheltered terrain. New snow, rain, wind and warming will add stress to these layers and they may become reactive.
Storm slabs sit on a weak interface and are reactive with new snow, strong southerly wind.
The stormy conditions have proved a widespread and ongoing natural avalanche cycle up to size 3. Many of these avalanches have been reported as wind, storm and persistent slabs at upper elevations and wet loose at lower elevations.
We suspect natural activity will continue on Friday. Leading into the weekend, natural avalanches may taper, but conditions could remain primed for human triggering.
Over the past few days, up to 50 cm of new storm snow accompanied by strong southerly wind hit the region. Wind-transported snow has likely built deeper slabs on northerly aspects at upper elevations. Lower elevation snow may be crusty as freezing levels fall.
The upper metre of the snowpack is complicated. This snow sits above several significant weak layers that formed during the January and February dry spells. These include facets, surface hoar (in sheltered terrain), and crust on solar aspects.
A layer of facets on top of a crust from early December is buried 100 to 200 cm deep. This layer is generally not a concern in this region.
Thursday Night
Cloudy. 20 to 30 km/h south ridgetop wind. Treeline temperature -3 °C. Freezing level 700 m.
Friday
Cloudy with 5 to 10 mm/cm of rain/snow. 20 to 40 km/h south ridgetop wind. Treeline temperature -1 °C. Freezing level 900 m.
Saturday
Cloudy with a trace of snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperatures -4. Freezing level 1100 m.
Sunday
Sunny by the afternoon. 10 to 20 km/h northwest ridgetop wind. Treeline temperatures -7. Freezing level 1200 m.
More details can be found in the Mountain Weather Forecast.
