New snow, wind and warming will likely stiffen the upper snowpack. Wind and persistent slabs may be reactive to human triggering.
Avoid slopes that feel and look "slabby".
Fresh and reactive wind slabs are likely. Wind slabs will be the most sensitive where they overlie facets.
Dry loose avalanches may be seen from steep slopes in wind sheltered terrain.
Concerning weak layers formed in January and February. They exist in the upper 80 cm of the snowpack. New snow, wind and warming will add stress to these layers and may become reactive.
On Friday, a natural wind slab (12 hours old) was observed in a zone called the Onion. This released on a north aspect at 1650 m.
On Thursday, the NW Field Team triggered a (size 1.5) wind slab on an east facing slope at 1740 m. The crown was 40 cm thick, 50 m wide and ran 100 m. It ran on the faceted layer below.
Wind loaded slopes at upper elevations are most suspect and may be primed for human triggered slab avalanches through the weekend.
Warm temperatures, new snow and strong wind are stiffening the upper (40 to 60 cm) of the snowpack, forming a more cohesive slab. Deeper deposits of wind loaded snow can be found at treeline and above on northerly facing slopes. South facing slopes have been scoured by the wind. Loose, low-density snow exists in terrain sheltered from the wind.
This slab sits above a variety of old snow surfaces, including soft, faceted snow in sheltered terrain and wind-affected snow in exposed terrain. This layer is showing reactivity in snowpack testing.
A facet/crust layer from early December is buried approximately 70 to 110 cm deep. This layer is generally not a concern in this region at this time.
Friday Night
Cloudy with 5 to 10 cm of snow. 10 to 35 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1100 m.
Saturday
Cloudy with sunny periods and isolated flurries. 20 to 45 km/h south ridgetop wind. Treeline temperature 0 °C. Freezing level 1500 m.
Sunday
A mix of sun and cloud. 10 to 20 km/h northwest ridgetop wind. Treeline temperatures 0°C. Freezing level 1300 m.
Monday
Sunny with few cloud. 10 to 20 km/h northeast ridgetop wind. Treeline temperatures -1 °C. Freezing level 1300 m.
More details can be found in the Mountain Weather Forecast.
