Dangerous avalanche conditions are developing as new snow and rain accumulates throughout the storm.
Travel in avalanche terrain is not recommended.
We expect the persistent weak layer will get overloaded by a combination of new snow, wind and warming. Natural and human triggered avalanches are expected.
25 to 45 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.
Numerous size 1 to 2 dry and wet loose avalanches, both natural and rider-triggered occurred over the week.
Thursday, a size 1.5 naturally-triggered wind slab was reported in the Lizard Range.
Tuesday, there were two reports of size 1.5 skier and sled triggered persistent slabs in the alpine. See details in this MIN here and this MIN.
Looking forward, we expect avalanche activity to rapidly increase as snow starts to accumulate along with strong winds and warming.
Around 25 to 45 cm of new snow is expected to fall overnight and through Sunday, with the highest amounts forecast for the Lizard Range. At lower elevations this will fall as rain. The combined storm snow is covering old wind-affected surfaces in open areas, and 20 to 30 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, with no other layers of concern.
Saturday Night
Cloudy with 10 to 30 cm of snow / possible rain below 1800 m. 30 to 50 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1900 m.
Sunday
Mostly cloudy with 5 to 15 cm of snow / possible rain below 1800 m. 35 to 45 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level rising to 2000 m.
Monday
A mix of sun and cloud. 25 to 45 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level rising to 1700 m.
Tuesday
Cloudy with 2 to 10 cm of snow / possible rain below 1200 m. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level rising to 1600 m.
More details can be found in the Mountain Weather Forecast.
