Strong wind and heavy precipitation is creating dangerous avalanche conditions.
Avoid avalanche terrain during periods of heavy loading from wind and snow.
A weak layer of buried surface hoar and facets is worst at treeline in areas sheltered from previous strong south and west wind. Forecasted precipitation will be testing this layer.
Heavy overnight precipitation combined with strong winds are developing deep and reactive storm slabs at treeline and above. The western part of the region will see the highest amounts of storm snow.
On Saturday, skier-triggered wind slabs up to size 1.5 were observed at treeline, including a remotely triggered size 2 wind slab.
On Friday, there were a few large skier-triggered persistent slabs failing at treeline. It is suspected they both failed on surface hoar and/or sugary facets over a crust buried 30-50 cm deep.
Up to 60 cm of storm snow overnight has buried wind affected snow.
This sits on a spotty layer of surface hoar on a crust that is 60 to .
The base of the snowpack has a few crusts from early in the season that are not currently a concern.
Sunday Night
Cloudy. 60 cm of snow at treeline. 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1600 m.
Monday
Cloudy. 35 cm snow at treeline. 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1700 m.
Tuesday
Mostly cloudy. 2 to 10 mm of rain at treeline. 40 km/h southwest ridgetop wind. Treeline temperature 2 °C. Freezing level 2500 m.
Wednesday
Mostly sunny. 1 mm of rain at treeline. 40 km/h southwest ridgetop wind. Treeline temperature 2 °C. Freezing level 2400 m.
More details can be found in the Mountain Weather Forecast.
