Avalanche Forecast

Moderate

• Forecast precipitation (either snow or rain) amounts are uncertain.
• Uncertainty is due to difficult to forecast freezing levels.

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.

• Continue to make conservative terrain choices while the storm snow settles and stabilizes.
• Be alert to conditions that change with elevation, aspect, and exposure to wind.
• Use ridges or ribs to avoid areas of wind-loaded snow.
• Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.