South Columbia

Assess the bond between wind slabs and the underlying crust before committing to steep terrain.

Strong sun could increase the likelihood of both natural and human-triggered avalanches.

High

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

Avalanche activity slowed over the weekend. Most reports were small (size 1) wind slab and cornice avalanches on north- and east-facing alpine terrain, with one large skier-triggered wind slab (size 2.5) north of Golden on Saturday.

Wind slabs are consistently failing on the atmospheric river crust, and poor bonding to this crusts suggests they may linger longer than usual.

5 to 15 cm of soft snow fell Sunday over wind-hardened snow and wind slabs.

Convective flurries this past week have created variable accumulations across the region. In total, 30 to 80 cm of snow overlies a thick crust from the recent atmospheric river, which extends up to at least 2300 m.

Weak layers from February exist 150 cm and deeper, with no recent reactivity.

Monday Night

Clear skies. 20 km/h west ridgetop wind. Treeline temperature -10 °C.

Tuesday

Mostly sunny. 20 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Wednesday

Mix of sun and clouds. 1 to 2 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -3 °C.

Thursday

Mix of sun and clouds. 1 to 3 cm of snow. 20 km/h southeast ridgetop wind. Treeline temperature -1 °C. Freezing level 2000 m.

More details can be found in the Mountain Weather Forecast.

• Be careful as you transition into wind-affected terrain.
• Keep in mind a buried crust offers an excellent bed surface for avalanches.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
• Be alert to conditions that change with elevation and sun exposure.