Avalanche Forecast
Regions: Bull, East Purcell, Purcells.
Deeply buried weak layers are expected to become active with rising freezing levels.
Choose conservative terrain free of overhead hazards.
Confidence
Moderate
Avalanche Summary
There have been many large (size 2) to very large (size 4) rider-triggered avalanches on deeply buried weak layers in the Purcells this week. Mainly in the alpine but with whumpfing reported below treeline as well.
Snowpack Summary
There are various old surfaces including recent snow settling, wind-affected snow, and sugary facets.
The mid-snowpack has a couple of crusts and is generally faceted and weak above them.
At the base of the snowpack, weak faceted grains and depth hoar are present.
Weather Summary
Saturday Night
Cloudy with a trace of snow, southwest alpine wind 15 to 30 km/h, treeline temperature -2 °C.
Sunday
Mostly cloudy with 5 to 10 cm of snow, southwest alpine wind 20 to 40 km/h, treeline temperature 0 °C, freezing level 2000 m.
Monday
Mostly cloudy with no new snow, southwest alpine wind 30 to 50 km/h, treeline temperature 3 °C, freezing level 2500 m.
Tuesday
Mostly cloudy with a trace of snow, southwest alpine wind 20 to 40 km/h, treeline temperature 3 °C, freezing level 2200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Avalanche Problems
Persistent Slabs
The snowpack is weak and facetted. This MIN captures the problem well. If triggered it could step down to the deep persistent problem.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5
Deep Persistent Slabs
If triggered, this problem will likely be the full depth of the snowpack and could run below treeline. Avoid shallow, rocky start zones.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3
Loose Wet
Even small avalanches could step down to deeply buried weak layers.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5