Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Rising temperatures and sunshine will increase avalanche danger. Buried weak layers continue to produce large avalanches that may run to valley bottom.
Confidence
Moderate
Avalanche Summary
On Tuesday, there were several natural and rider-controlled wind slabs, mostly small, but some up to size 2. As well as some wet loose avalanches below treeline. There was also a recent large persistent slab (size 2.5) seen near Panorama that is suspected to have occurred in the past 3 days. From a northeast aspect in the alpine.
Snowpack Summary
Around 10 to 30 cm of new snow, with the most on the west side of the region, sits over a crust or moist snow. Surface snow at lower elevations is expected to be wet and likely form into a crust.
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 there is no thick crust above them.
The base of the snowpack is generally faceted.
Weather Summary
Wednesday Night
Partly cloudy. 15 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Thursday
Mostly sunny. 20 to 40 km/h south ridgetop wind. Treeline temperature 0 °C. Freezing level 2500 m.
Friday
A mix of sun and cloud with up to 10 cm of snow ending in the morning. 20 km/h southwest ridgetop wind. Treeline temperature 0 °C.
Saturday
Mostly cloudy with 5 to 10 cm of snow. 10 km/h southwest ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Even brief periods of direct sun could produce natural avalanches.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Be aware of the potential for large avalanches due to buried weak layers.
Avalanche Problems
Storm Slabs
Recent snow isn't bonding well to the crust and may fail as a slab or loose snow. This problem seems to get worse the further west you go, where there is more new snow above the crust.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Persistent Slabs
Several persistent weak layers exist in the upper meter of the snowpack. The likelihood of persistent slab avalanches will increase if the melt-freeze crust near the surface breaks down.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2.5 - 3.5
Cornices
Cornices are weak and may break further back on ridgelines than expected. These large loads can trigger buried weak layers on the slope below.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5