Avalanche Forecast

A large cornice failed west of Brisco on Sunday which didn't trigger a slab on the slope below.

On Friday, a helicopter landing on a slope remotely triggered several large (size 2) persistent slab avalanches on a north aspect in the alpine south of Golden. The avalanches failed on the crust which was down 80 to 110 cm in that location.

5 to 15 cm of recent snow overlies predominantly crusty surfaces, except for northerly aspects at upper elevations.

A widespread crust with sugary facets above is down 40 to 110 cm. Steep or convex terrain features with a shallow or thin to thick snowpack at treeline and above are the most likely places to trigger this layer. However, when a thick surface crust is present, human triggering this layer is unlikely.

The bottom of the snowpack is generally weak and faceted, with the potential to produce very large avalanches.

Tuesday Night

Partly cloudy with up to 2 cm of snow. 10 to 20 km/h west alpine wind. Treeline temperature -5 °C.

Wednesday

Partly cloudy with 1 to 2 cm of snow. 10 to 20 km/h southwest alpine wind. Treeline temperature -4 °C. Freezing level rising to 1700 m.

Mostly cloudy with up to 10 cm of snow. 10 km/h southwest alpine wind. Treeline temperature -4 °C. Freezing level 1700 m.

Mostly cloudy with up to 10 cm of snow. 15 km/h southwest alpine wind.  Treeline temperature -4 °C. Freezing level 1700 m.

More details can be found in the Mountain Weather Forecast.

• Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
• When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
• Conditions may have improved, but be mindful that deep instabilities are still present.
• Cornice failure may trigger large avalanches.