Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
Confidence
Moderate
Avalanche Summary
On Thursday, several naturally triggered size 2 persistent slabs were reported on northerly and east aspects in the alpine.
Additionally a sledder remotely triggered two size 1.5 storm slabs from 60 m. away. They occurred on a easterly aspect in a alpine bowl feature at treeline.
Snowpack Summary
5 to 15 cm of recent snow and southwest wind have formed small wind slabs on lee aspects at treeline and above.
30 - 50 cm of snow overlies a crust on sunny slopes and lower elevations, and surface hoar or facets on sheltered and shady upper elevations.
Several persistent weak layers consisting of a crust, facets, and/or surface hoar from February and January remain a concern. They are down 50 to 100 cm in most areas.
The bottom of the snowpack is composed of large facets in most areas. There is evidence that this layer is becoming reactive again, and some very large avalanches have failed on this layer recently.
Weather Summary
Friday night
Partly cloudy with 0 to 10 cm of snow. 10 to 20 km/h west ridgetop winds. Treeline temperature -8 °C. Freezing level valley bottom.
Saturday
Mix of sun and cloud. 10 to 20 km/h west winds. Treeline temperature -5 °C. Freezing level 1500 m.
Sunday
Mix of sun and cloud. 10 to 20 km/h southwest ridgetop winds. Treeline temperature -2 °C. Freezing level 1800 m.
Monday
Moslty sunny. 20 to 30 km/h west ridgetop winds. Treeline temperature 1 °C. Freezing level rapidly rising to 2100 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
- Be aware of the potential for large, destructive avalanches due to deeply buried weak layers.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Even brief periods of direct sun could produce natural avalanches.
Avalanche Problems
Persistent Slabs
Triggering buried weak layers is most likely in wind-affected terrain on northerly and easterly aspects. Small avalanches in motion may trigger these deeper layers creating very large and destructive avalanches.
Aspects: North, North East, East, West, North West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 3
Wind Slabs
5 to 15 cm of recent snow and southwest wind have formed small wind slabs on lee aspects at treeline and above.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Loose Wet
Expect strong solar radiation to trigger small wet loose avalanches and increase the likelihood of triggering slabs.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1.5