Avalanche Forecast

Evidence of a natural avalanche cycle up to size 2.5 was reported Wednesday. During the day storm snow was very reactive to rider traffic, including remotely triggered avalanches to size 2. Most storm slab avalanches were 40-60 cm deep and many reportedly ran on surface hoar buried on Jan 4. A few size 1-2 wind slabs 30-60 cm deep were triggered by rider traffic, these occurred on north-to-east aspects above 2200 m.

Roughly 30-60 cm of new snow fell in the region early this week. It buried moderately wind-affected surfaces in exposed areas at higher elevations but mainly added to 30-60 cm of storm snow from Saturday. All this snow collectively sits on an aspect and elevation-dependent mix of crusts, surface hoar, and facets. Areas where surface hoar may be preserved are a concern.

A crust formed by early December rain is found ~70 cm deep, and an old layer of surface hoar 60-100 cm deep. Recent observations suggest triggering this layer is unlikely. The lower snowpack is variable throughout the region and weak basal facets are likely to be found on the ground in shallow snowpack areas.

Thursday Night

Mainly cloudy. Variable, mainly northwest alpine wind 10-20 km/h. Treeline temperature -35°C.

Friday

Mostly sunny. North alpine wind 10-20 km/h. Treeline temperature -30°C.

Saturday

Sunny. Variable alpine wind, gusting to 40 km/h at ridgetop. Treeline temperature -30°C.

Sunday

Increasing clouds. Northwest alpine wind 20-30 km/h. Treeline temperature -30°C.

More details can be found in the Mountain Weather Forecast.

• Watch for areas of hard wind slab on alpine features.
• Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.