Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Continue to make conservative terrain choices and avoid shallow rocky slopes.
In General the snowpack is weak and there is an ongoing risk of triggering a deep persistent slab.
Confidence
Moderate
Avalanche Summary
On Monday evening we received reports of a fatal avalanche accident. This Avalanche occurred on a west facing slope at treeline in the southern Selkirk mountains. This avalanche did not occurre in this forecast region but similar snowpack conditions exist in the Purcells. This MIN report has more details.
Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Wind effected surfaces exist on exposed treeline and alpine features. A new surface hoar layer can be found just below the surface as well as a crust on some steep south facing slopes.
The upper snowpack continues to settle and bond with mild temperatures. The mid and lower snowpack is generally weak and faceted, with a number of weak layers. Of significant concern is a layer down 30 to 50 cm from the surface consisting of a crust, facets, and/or surface hoar. And a layer of large facets and a crust down roughly 50 to 110 cm from the surface. The snow below this deeper weak layer is unconsolidated and weak.
Snowpack depths remain highly variable, ranging from 60 to 150 cm at treeline.
Weather Summary
Tuesday Night
Cloudy with trace amounts of new snow expected. Light southwest winds and a low of -12 at 1800m.
Wednesday
Cloudy with some sunny breaks and the possibility light flurries bringing trace amounts of new snow. Light southerly winds and a high of -6 at 1800m.
Thursday
Cloudy with up to 5cm of new snow expected. Strong southerly winds and freezing levels rising to 1500m.
Friday
Stormy with up to 10cm of new snow expected at treeline and above. Rain at lower elevations. Freezing levels around 1900m . Moderate to strong southerly winds.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
Avalanche Problems
Deep Persistent Slabs
A weak layer near the base of the snowpack, buried in November, remains a concern despite lack of recent avalanche activity. Human triggering of this layer remains possible, especially in shallow areas with variable snow depths.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5
Persistent Slabs
A layer of surface hoar, facets and/or a crust may be found around 40 to 70 cm deep, which is a prime depth for human triggering. Of more concern at the treeline elevations and below.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2.5