Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells.
Stick to mellow terrain, and avoid travelling in or under large, open slopes.
Avoid thin and rocky start zones, a problematic persistent weak layer continues to haunt us.
Confidence
Moderate
Avalanche Summary
On monday, a couple of rider controlled cornices pulled out small slab avalanches on the slope below. Reactivity to human triggers is expected to continue.
Human triggering of very large persistent slab avalanches continues with a size 2 triggered over the weekend. A notable remotely triggered avalanche occurred near Golden on Thursday. And a fatal avalanche occurred in nearby Kananaskis Country on Sunday, where a similar snowpack structure exists.
Snowpack Summary
15-30 cm of low density snow sits over sun crusts on south facing slopes, wind-affected snow at higher elevations, and small surface hoar crystals on settling snow elsewhere. In wind exposed terrain, new cornices and wind slabs have continued to form.
A widespread crust is buried roughly 80-120 cm deep. Weak faceted crystals and surface hoar above this crust are contributing to large avalanches across the province and continue to be the primary layer of concern here.
Additionally, the lower snowpack is mostly made up of weak and faceted layers.
Weather Summary
Tuesday Night
Mostly clear. 0-2 cm of snow expected. Light southwest ridgetop wind. Freezing level falls to 900 m. Treeline low around -5 °C.
Wednesday
Mostly cloudy. 0-1 cm of snow expected. Light southwest ridgetop wind. Freezing levels rise to 1700 m. Treeline temperature -3 °C.
Thursday
Sunny. No new snow expected. Light northwest ridgetop wind. Freezing level at valley bottom overnight, rising to 1800 m. Treeline temperature -3°C.
Friday
Mostly sunny. No new snow expected. Light northwest ridgetop wind. Freezing level at valley bottom overnight, rising to 2900 m. Treeline temperature 3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Avoid avalanche terrain during periods of strong sun.
Avalanche Problems
Persistent Slabs
Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.
Stick to simple terrain features to minimize exposure to this problem.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3.5
Wind Slabs
Reactive wind slabs likely exist on north and east facing slopes around ridgelines. 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: Possible - Likely
Expected Size: 1 - 2