Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Avalanche danger may be decreasing, however, the consequences of triggering any avalanche could be severe due to a persistent weakness deep within the snowpack.
Confidence
Moderate
Avalanche Summary
Several explosive-triggered storm and wind slab avalanches were reported over the weekend up to size 2, on a variety of aspects and elevations.
Last week a few explosive-triggered deep persistent slab avalanches (size 2.5 to 3.5) were reported, all in the northwest of the forecast region. These avalanches occurred in areas characterized by generally deeper snowpacks compared to most other areas. All avalanches took place in north-facing alpine terrain.
Snowpack Summary
The upper snowpack continues to settle with mild temperatures. In wind-exposed terrain at treeline and above, recent snow has potentially been redistributed into deeper pockets of wind slabs by predominantly southwest winds.
A layer of faceted snow exists down approximately 30 to 40 cm, created during the extreme cold earlier this month.
The mid and lower snowpack is generally weak with several layers of note. Of greatest concern is a well preserved layer of weak facets and/or depth hoar located at the bottom of the snowpack, particularly in alpine terrain.
Weather Summary
Monday Night
Mostly cloudy with 0 to 5 cm of snow, southwest alpine winds 20 to 30 km/h, treeline temperature -4 °C.
Tuesday
Mostly cloudy with trace snow amounts, west alpine winds 20 to 30 km/h, treeline temperature -5 °C.
Wednesday
Mix of sun and cloud with trace snow amounts, southwest alpine winds 20 to 40 km/h, treeline temperature -7 °C.
Thursday
Mix of sun and cloud with trace snow amounts, west alpine winds 20 to 30 km/h, treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Conditions may have improved, but be mindful that deep instabilities are still present.
Avalanche Problems
Wind Slabs
Wind slabs persist in and around exposed-terrain features, like ridge tops and steep convexities (rollovers).
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2
Deep Persistent Slabs
There is a weak layer of facets and depth hoar near the base of the snowpack in most alpine areas. The likelihood of triggering a deep persistent slab is low, however, the consequences of doing so are high.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5