Northwest Inland

Wind slabs are a concern at all elevations on all aspects.

Avoid steep slopes that have been loaded by recent wind.

Moderate

• Uncertainty is due to how quickly the snowpack will recover and gain strength.
• Uncertainty is due to the limited number of field observations.

Reactive wind slabs were reported around Shames on Thursday. See this MIN post for more details.

Earlier in the week, a size 1.5 wind slab was reported in a cross-loaded feature at upper treeline. Given the cold temperatures, ongoing wind, and limited number of recent field observations, it is best to assume wind slabs may still be lingering in leeward terrain features in wind-affected terrain.

Strong, shifting winds have heavily affected alpine and treeline terrain, building wind slabs on many aspects and in some places extending into the trees.

More than 100 cm of heavy snow fell last week, which has strengthened the snowpack and reduced the chance of triggering older layers from early December (which include buried surface hoar and crusts).

Cold temperatures are expected to be faceting the snow surface. The new snowfall this weekend may bond poorly to this weak surface layer.

Snowpack depths exceed 350 cm at treeline.

Friday Night
Mostly clear skies. 10 km/h variable ridgetop wind. Treeline temperature -16 °C.

Saturday
Mostly cloudy. 2 to 5 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -13 °C.

Sunday
Mostly cloudy. 4 to 15 cm of snow. 70 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Monday
Mostly cloudy. 4 to 30 mm of precipitation as snow or rain at treeline. 70 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1800m.

More details can be found in the Mountain Weather Forecast.

• Investigate the bond of the recent snow before committing to your line.
• Be alert to conditions that change with elevation, aspect, and exposure to wind.
• Use ridges or ribs to avoid areas of wind-loaded snow.