Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells.
Danger may reach HIGH as mild temperatures and strong sunshine weaken the snowpack. Large natural avalanches may occur.
Choose small, low angle slopes free from overhead hazard.
Confidence
High
Avalanche Summary
Numerous very large natural and explosive-triggered persistent slab avalanches have been reported (size 2 to 3.5) this week. Natural activity appears to be tapering off, and while fewer human triggered avalanches have occurred in the last few days, reports indicate triggering is still very possible - as shown by this remotely triggered avalanche near Golden on Thursday.
The photos below show the type of terrain and typical size for these avalanches.
Snowpack Summary
Surface conditions currently include sun crusts on south facing slopes, lightly wind-affected snow, and settling snow.
A widespread crust that formed in early February is roughly 80-120 cm deep. Weak faceted crystals and surface hoar above this crust are contributing to large avalanches across the province.
Additionally, the lower snowpack is mostly made up of weak and faceted layers.
Weather Summary
Friday Night
Mostly clear skies. 20-40 km/h southwest ridgetop wind. Freezing level drops to valley bottom.
Saturday
Mostly clear skies. 30-50 km/h south ridgetop wind. Freezing levels rise to 1800 m by the afternoon. Treeline temperature -2 °C.
Sunday
Mostly cloudy with 1-5 cm of snow. 20-40 km/h south ridgetop wind. Freezing levels rise to 1500 m by the afternoon. Treeline temperature -4 °C.
Monday
Mostly cloudy. 10-20 km/h south ridgetop wind. Freezing levels rise to 1500 m by the afternoon. Treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Conservative terrain selection is critical, choose only well supported, low consequence lines.
- Avoid being on or under sun exposed slopes.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.
Avalanche Problems
Persistent Slabs
Remote triggering of this layer continues. Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 2 - 3.5
Loose Wet
Wet avalanches are more likely on steep, sun affected slopes. Avoid slopes that have moist or wet surface snow.
Aspects: East, South East, South, South West.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2
Wind Slabs
Winds have picked up and loose snow is available to build fresh and reactive wind slabs. Small wind slabs could step down to deeper weak layers producing very large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 1.5