Avalanche Forecast
Regions: Crawford, Dogtooth, East Purcell, Esplanade, Purcells, St. Mary, West Purcell.
A complex snowpack exists, with multiple layers of concern that may vary across different locations.
Confidence
Moderate
Avalanche Summary
On Monday, a size 1, skier-triggered persistent slab avalanche was reported in the Crawford area. It occurred on a northwest aspect at treeline.
There have been numerous natural and skier-triggered very large (up to size 3) persistent slab avalanches reported on all aspects at treeline and above in the Esplanade range over the past week. They've occurred on a layer of surface hoar down 50-70 cm.
Snowpack Summary
The upper snowpack continues to settle with mild temperatures and minimal wind.
A layer of buried surface hoar is down roughly 50 to 70 cm and remains concerning in much of the region. It is less of a concern in areas where a strong, supportive crust exists above the surface hoar layer.
As you move south in the region, weak facets near the ground are a concern. Especially in shallow, rocky areas in alpine terrain.
Average snowpack depths at treeline are 70-120 cm which tapers rapidly below treeline.
Weather Summary
Wednesday Night
Cloud building overnight with no precipitation, south alpine winds 0 to 20 km/h, treeline temperature -8 °C.
Thursday
Mostly cloudy with no precipitation, southwest alpine winds 0 to 20 km/h, treeline temperature -6 °C.
Friday
Mix of sun and cloud with no precipitation, southeast alpine winds 0 to 20 km/h, treeline temperature -6 °C.
Saturday
Mix of sun and cloud with no precipitation, southeast alpine winds 0 to 20 km/h, treeline temperature -4 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- In times of uncertainty conservative terrain choices are our best defense.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Avalanche Problems
Persistent Slabs
The primary layer of concern in much of the region is a layer of surface hoar down 50-70 cm. If triggered, avalanches on this layer could step down to deeper weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3
Deep Persistent Slabs
A layer of weak facets near the ground may be reactive to human triggering. Especially in shallow, rocky areas in alpine terrain where the layer is not being capped by a crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1.5 - 3