Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Another warm-up brings rising avalanche risk.
Uncertainty remains about cornice falls or surface instabilities stepping down to persistent weak layers.
Confidence
Moderate
Avalanche Summary
Two large natural persistent slabs (size 2) were naturally triggered from thin rocky northerly terrain near Panorama. Several dry loose and wind slabs also occurred naturally and skier-triggered in the region on Thursday.
Over the past 5 days, explosives were used to drop cornices, some of which triggered persistent slabs on the slopes below. The resulting avalanches were up to size 3 with crowns as deep as 3 meters.
Snowpack Summary
A diurnal melt-freeze cycle occurred in the past days. The surface is either moist or capped with a thin crust on all aspects and elevations except for high northerly slopes where up to 30 cm overlies a thick crust from late March.
Several weak layers from early March, mid-February and late January can be found in the mid and lower snowpack. These layers remain a concern where a thick crust isn’t present above.
The base of the snowpack is generally faceted.
Weather Summary
Friday Night
Clear. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level around 1000 m.
Saturday
Sunny. 10 to 20 km/h southeast ridgetop wind. Treeline temperature +4 °C. Freezing level rising to 2500 m.
Sunday
Sunny. 10 to 20 km/h southeast ridgetop wind. Treeline temperature +6 °C. Freezing level rising to 3000 m.
Monday
Mix of sun and clouds. 20 to 40 km/h west ridgetop wind. Treeline temperature +4 °C. Freezing level around 2500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avalanche danger is expected to increase throughout the day.
- Avoid areas with a thin or variable snowpack.
- Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Avalanche Problems
Loose Wet
As surfaces become wet, loose wet avalanches will become more likely on steep south-facing slopes at all elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 1.5
Cornices
Cornices have failed naturally in the region recently. Avoid travelling on slopes below cornices.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5
Persistent Slabs
Various weak layers from the past 3 months are a concern in shallow north-facing terrain. Surface instabilities or large triggers such as cornices may step down to these deeper layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2.5 - 3.5