Assess for slabs as new snow accumulates with strong wind.
Wind slabs could be triggered in lee terrain features at higher elevations. It is possible that riders could also trigger storm slabs as new snow accumulates, particularly where they rest on a weak layer in sheltered treeline terrain.
Riders triggered small slabs in lee terrain features on the weekend (e.g., here). We also received a report of a rider triggering a small avalanche on the surface hoar layer described in the Snowpack Summary at treeline. This MIN report may have also occurred on this layer. Naturally triggered wet loose avalanches were also noted on steep sun-exposed slopes.
Around 5 to 15 cm of snow is forecast to accumulate by Tuesday afternoon with associated strong southwest wind. New slabs may form, particularly in lee terrain features. This snow will sit on old, hard wind slabs in wind-exposed terrain and otherwise settled snow.
A layer of surface hoar may be found about 30 to 40 cm deep in treeline and open below treeline areas sheltered from the wind. A hard crust and associated facetted grains from December is about 60 cm deep at treeline elevations.
The rest of the snowpack is strong and well-settled.
Monday Night
Cloudy with 2 to 5 cm snow, southwest alpine wind 20 to 40 km/h, treeline temperature -3 °C.
Tuesday
Cloudy with 5 to 10 cm snow, southwest alpine wind 30 to 50 km/h, treeline temperature -2 °C, freezing level 800 m.
Wednesday
Mostly cloudy with 2 to 5 cm snow, southeast alpine wind 20 km/h, treeline temperature -3 °C.
Thursday
Mostly cloudy with 2 to 5 cm snow, southwest alpine wind 20 to 40 km/h, treeline temperature -2 °C.
More details can be found in the Mountain Weather Forecast.
