Avalanche Forecast
Regions: Bull, Dogtooth, East Purcell, Purcells, West Purcell.
If a thick, hard surface crust is present, avalanche activity is unlikely.
Buried weak layers continue to produce sporadic large avalanches on high-elevation northerly slopes.
Confidence
Moderate
Avalanche Summary
Friday, a deep persistent slab was triggered by sledders east of Wasa (see photo below).Several wind slabs up to size 2 also occurred in the Western Purcells on lee alpine slopes.
Thursday, a few large cornice failures were triggered with warming, along with a large (size 2.5) wind slab on a northwest alpine slope.
Snowpack Summary
Lower elevations and slopes that face the sun generally have a thick surface crust that can soften and become moist or wet with sun and daytime warming. Shady northerly alpine slopes likely still have dry snow and may have some lingering wind slabs.
Several persistent weak layers of crusts and/or facets can be found in the mid and lower snowpack. These layers remain a concern where there is no thick and supportive crust above them.
The base of the snowpack is generally faceted. Lower elevations are rapidly melting out.
Weather Summary
Sunday Night
Clear. 10 to 15 km/h northwest ridgetop wind. Treeline temperature -6 °C. Freezing level 1800 m, then falling to valley bottom.
Monday
Sunny. 5 to 15 km/h northwest ridgetop wind. Treeline temperature +3 °C. Freezing level rising to 2500 m.
Tuesday
A mix of sun and cloud. 15 to 25 km/h southwest ridgetop wind. Treeline temperature +2 °C. Freezing level rising to 2400 m.
Wednesday
Mostly sunny. 20 to 30 km/h northwest ridgetop wind. Treeline temperature -2 °C. Freezing level rising to 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs are isolated, but may remain reactive.
- 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 activity is unlikely when a thick melt-freeze crust is present on the snow surface.
Avalanche Problems
Persistent Slabs
Several persistent weak layers exist in the mid to lower snowpack. Persistent slab avalanches may be possible to trigger on northerly upper-elevation slopes where there is no thick supportive crust on the surface.
Aspects: North, North East, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5
Wind Slabs
Lingering isolated wind slabs may be triggerable on leeward upper elevation slopes with no surface crust.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2
Loose Wet
Remain cautious on sun-exposed slopes during the warmest parts of the day, especially if the snow surface is moist or wet. Use appropriate sluff management techniques.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 1.5