Avalanche Forecast

Moderate

We are within a period of significant avalanche activity in the Purcells, with many notable large persistent slab avalanches (e.g., this one near Golden). Buried weak layers have been easily triggered by riders and with explosives, with numerous size 2 to 3 slabs reported over the past week. These avalanches have mostly been in alpine terrain and have propagated widely across terrain features.

Triggering large persistent slab avalanches may remain a concern for a while within this region.

Roughly 40 cm of recent snow has settled into a slab that overlies weak faceted grains. The snow is also stressing buried weak layers, including:

• A surface hoar layer buried in mid-December that is 40 to 60 cm deep

• Weak faceted snow and decomposing crusts near the bottom of the snowpack, ranging from 70 to 150 cm deep.

These layers have produced large avalanches over the past week and need more time to strengthen.

Sunday Night

Clear skies with no precipitation, 10 km/h southwest wind, treeline temperature -9 °C.

Monday

Sunny with no precipitation, 10 km/h south wind, treeline temperature -6 °C.

Mostly sunny with no precipitation, 10 km/h south wind, treeline temperature -7 °C.

Cloudy with isolated flurries, 20 to 40 km/h southwest wind, treeline temperature -11 °C.

More details can be found in the Mountain Weather Forecast.

• Choose conservative terrain and watch for clues of instability.
• Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
• Remote triggering is a concern, watch out for adjacent and overhead slopes.
• Back off if you encounter whumpfing, hollow sounds, or shooting cracks.