Avalanche Forecast
Regions: Purcells.
Confidence
Fair - Freezing levels are uncertain
Weather Forecast
Wednesday-Friday: Strong north-westerly winds. Freezing level is at valley bottom, with alpine inversions possible (parcels of warm air which could bring alpine temperatures close to 0). Generally only trace amounts of snow.
Avalanche Summary
Several size 1-2 wind slabs were triggered naturally and by skiers on Tuesday morning. Wind slabs were also triggered remotely by a skier and a helicopter on Monday on steep lee slopes.
Snowpack Summary
Strong north-westerly winds have left hard and soft wind slabs in the lee of ridges and ribs at alpine and treeline elevations. Recent storm snow is settling over old snow surfaces including surface hoar (found especially at and below treeline in sheltered areas), a sun crust (on steep S to SW -facing slopes) and facets. The distribution of these weaknesses is patchy, but where they exist, it is still possible to trigger a large avalanche with the weight of a person or snowmobile. Watch out for rapid warming on alpine slopes over the next couple of days, which could weaken the slab above these interfaces. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.
Avalanche Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 5
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 5