South Columbia

Keep your head up and know what’s above you.

Solar input could increase the likelihood of cornices failing naturally.

High

• We have a good understanding of the snowpack structure and confidence in the weather forecast.

On Tuesday several natural cornice failures were reported. Even without triggering a slab on the slope below the debris was up to size 2.5.

Shaded, sheltered slopes may have up to 20 cm of low-density powder, while wind slabs can be found in the immediate lee of features. Sun exposed slopes have a crust that will likely soften with solar input.

Convective flurries over the past two weeks have deposited highly variable amounts of snow above the atmospheric river crust. Depending on drainage and elevation, you may find 30 to 80 cm above this crust, which extends to at least 2300 m.

Older weak layers are unreactive and buried at least 150 cm deep.

Wednesday Night
Partly cloudy. 10 km/h southeast ridgetop wind. Treeline temperature -4 °C.

Thursday
Mix of sun and clouds. 20 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1600 m.

Friday
Mostly cloudy. 1 to 2 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -3 °C.

Saturday
Mostly cloudy. 1 to 10 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -3 °C.

More details can be found in the Mountain Weather Forecast.

• Pay attention to cornices and give them a wide berth when traveling on or below ridges.
• Carefully evaluate steep lines for wind slabs.
• Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
• Keep in mind a buried crust offers an excellent bed surface for avalanches.