Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells.
A deep persistent slab problem remains where the near-surface crust is thin or absent.
Low-probability, high-consequence problems are best managed with conservative terrain choices.
Confidence
Moderate
Avalanche Summary
On Monday, natural loose dry avalanches were reported to size 1 in steep polar aspects.
Over the weekend, several wind slab and loose avalanches were reported, up to size 1.5, in steep alpine terrain, some triggered by humans, and some by the sun.
Snowpack Summary
1 to 5 cm of snow overlies wind affected surfaces in open areas and a sun crust on solar slopes.
In sheltered areas, 10 to 30 cm of settling snow sits over a frozen crust that formed in early February. This crust is generally supportive to the weight of a human below treeline, but becomes breakable around treeline, and disappears as you ascend higher into the alpine.
The midpack is generally faceted.
The bottom 15-30 cm of the snowpack consists of weak faceted grains, depth hoar, and crusts that continue to produce sporadic, large avalanches.
Weather Summary
Tuesday Night
Mostly cloudy. 0 to 5 cm of snow. 10 to 25 km/h southwest ridgetop wind. Treeline temperature around -3 °C. Freezing level rising to 1200 m.
Wednesday
Partly cloudy. 0 to 2 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature around -2 °C. Freezing level rising to 1700 m.Â
Thursday
A mix of sun and cloud. 20 to 30 km/h southwest ridgetop wind. Treeline temperature around -1 °C. Freezing level rising to 1700 m.
Friday
A mix of sun and cloud. 10 to 25 km/h west ridgetop wind. Treeline temperature around 0°C. Freezing level rising to 1900 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Conditions may have improved, but be mindful that deep instabilities are still present.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Avalanche Problems
Deep Persistent Slabs
A weak layer near the base of the snowpack is a concern where a thick, strong, near-surface crust does not exist. This could be at higher elevations in the alpine and in steep, rocky, open features at treeline,
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2 - 3.5
Wind Slabs
Wind slabs are slowly bonding, or are getting softer and less reactive due to near-surface faceting. It is still possible for the weight of a human to trigger a small wind slab avalanche.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 1.5