Danger will be HIGH in areas that recieve more than 20 cm of new snow.
In times of uncertainty, conservative terrain choices are our best defense.
A weak layer of surface hoar and/or facets is buried 40 to 60 cm and may become overloaded as precipitation accumulates. Remote triggering is a concern, avoid overhead hazard.
10 to 20 cm of new snow combined with southwesterly winds will build reactive storm slabs. At lower elevations it will rain, making wet slabs and loose wet avalanches likely.
On Thursday, explosives triggered a size 2 wind slab near Castle Mountain.
On Wednesday, a large (size 2.5) persistent slab failed on a north-facing alpine slope near Line Creek.
On Tuesday, there were reports of large (size 2) dry loose avalanches running in steep terrain. These were stepping down to a weak layer of facets buried in late January.
Looking forward, we expect avalanche activity to increase as snow starts to accumulate along with strong winds and warming.
10 to 20 cm of new snow is expected to accumulate overnight and through Sunday, accompanied by moderate to strong southwesterly wind. At lower elevations this will fall as rain. The new snow will cover old wind slabs and wind-affected surfaces in open areas, and around 25 cm of settling snow overlying facetted snow in wind-sheltered areas. A persistent weak layer of surface hoar or facets from late January is currently buried 40 to 60 cm. There is significant concern for this layer becoming active with the incoming precipitation and warming. The mid and lower snowpack is generally well settled.
Saturday Night
Cloudy with 5 to 15 cm of snow / rain possible below 1700m. 30 to 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 2000 m.
Sunday
Cloudy with 5 to 10 cm of snow / rain possible below 1700m. 30 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 2100 m.
Monday
A mix of sun and cloud. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level rising to 1900 m.
Tuesday
Cloudy with 0 to 3 cm of snow / rain possible below 1300 m. 35 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level rising to 1700 m.
More details can be found in the Mountain Weather Forecast.
