Avalanche Forecast
Regions: Dogtooth, East Purcell, Purcells, West Purcell.
Weak layers in the mid and lower snowpack are likely still reactive to human triggering. Stick to conservative terrain.
Confidence
Moderate
Avalanche Summary
Persistent slab avalanche activity seems to have tapered in the past few days. That being said, explosive control has consistently produced small to large (size 1.5 to 2.5) slab avalanches across the region over the past week. These avalanches all occurred above 2200 m and have failed on both surface hoar and facet layers.
There were reports few size of a size 1 wind slab avalanches on Friday.
Snowpack Summary
A dusting of new snow buried a recently formed surface hoar layer, sun crust, and wind-affected snow. A prominent rain crust is found 30 to 50 cm deep and has been reported to extend as high as 2300 m around Invermere and 2000 m around Golden. A layer of surface hoar is also found at this depth and is a particular concern in areas without a thick crust. The bottom of the snowpack contains large weak snow grains and in some places a hard crust near the ground. Typical snowpack depths at treeline are 60 to 110 cm, and taper rapidly below treeline.
Weather Summary
Saturday Night
Mainly cloudy with clear periods with, alpine wind southwest 15-30 km/h, treeline temperature -8 °C.
Sunday
Cloudy with sunny breaks, alpine wind west 20-40 km/h, treeline temperature -6 °C.
MondayMix of sun and cloud, alpine wind southwest 10-20 km/h, treeline temperature -5 °C.
TuesdayCloudy with flurries, alpine wind southwest 15-30 km/h, treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection and resist venturing out into complex terrain.
- Surface hoar distribution is highly variable. Avoid generalizing your observations.
- Be especially cautious as you transition into wind affected terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Avalanche Problems
Persistent Slabs
Choose terrain assuming there are buried weak layers capable of producing large avalanches. A 30 to 60 cm deep surface hoar layer is triggerable in areas without a rain crust, and weak facets sit at the base of the snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5
Wind Slabs
Wind slab avalanches may remain possible to trigger on leeward terrain features such as ridgecrests and roll-overs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2