Moderate wind and snowfall will keep the storm slab problem active.
Continue to make conservation terrain choices and share your observations via the Mountain Information Network.
Moderate snowfalls and wind created new storm/wind slabs. Expect them to be reactive to natural and human triggers, especially in freshly wind-loaded terrain features.
On Tuesday, several natural storm/wind slabs (size 1.5–2.5) were observed on north and east alpine slopes in the North Columbias.
Fast-running sluffing was also reported from steep, sheltered slopes throughout the region, both from natural and human triggers.
On Monday, explosive control work in West Purcells produced several large, loose dry avalanches (size 1.5-2.5) that failed within the recent storm snow on northerly alpine slopes.
Up to 20 cm of fresh snow overlies 80 to 110 cm of settling storm snow over a prominent hard crust formed in mid-December that extends up to 2300 m. Continued wind has redistributed the storm snow in exposed terrain at treeline and in the alpine.
Where the crust is thick and supportive, it effectively caps a few mid-snowpack instabilities, making them difficult to trigger. These layers, now over 175 cm deep, may still be a concern in the high alpine where the crust is thin or nonexistent.
Snowpack depth is around 250 cm at treeline, tapering with elevation below 1500 m.
Wednesday Night
Cloudy. 5 to 10 cm of snow. 50 km/h south ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.
Thursday
Mostly cloudy. 30 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Friday
Cloudy. 15 to 30 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -8 °C.
Saturday
Partly cloudy. 40 km/h northwest ridgetop wind. Treeline temperature -15 °C.
More details can be found in the Mountain Weather Forecast.
