Avalanche Forecast
Regions: Yukon.
Travel cautiously in wind-affected terrain, as touchy wind slabs exist.
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
MONDAY NIGHT: Cloudy with snowfall, accumulation 5 to 10 cm, 50 km/h south wind, alpine temperature -6 C.
TUESDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 60 km/h south wind, alpine temperature -4 C, freezing level rising to 900 m.
WEDNESDAY: Cloudy with snow and rain, accumulation 10 to 15 cm snow above 1200 m and rain below, 60 km/h south wind, alpine temperature -1 C, freezing level 1200 m.
THURSDAY: Early-morning snowfall then clear skies, accumulation 5 to 10 cm, 50 km/h southwest wind, alpine temperature -10 C.
Avalanche Summary
A widespread avalanche cycle occurred on the weekend for the closed South Klondike Highway area, with avalanches on north and east aspects (lee slopes) to size 3. This MIN also describes a couple skier-triggered wind slab avalanches in the Wheaton.
Looking forward, similar natural and skier-triggered wind slab avalanches are expected as stormy conditions continue.
Snowpack Summary
Strong south to southwest wind has blown any recent snow into touchy wind slabs in lee terrain features. The slabs may be widely variable in thickness, anywhere from 20 to upwards of 100 cm thick. A few reports suggest the slabs may have a poor bond with underlying surfaces, including previous hard wind slabs and potentially surface hoar crystals in sheltered and shaded terrain. It is possible that recent snow has formed storm slabs in the most sheltered of terrain that has avoided these perpetual winds.
In shallow snowpack areas, a layer of loose facets can be found at the bottom of the snowpack.
Terrain and Travel
- Avoid freshly wind loaded terrain features.
- Expect slab conditions to change drastically as you move into wind exposed terrain.
- Closely monitor how the new snow is bonding to the old surface.
- Make observations and assess conditions continually as you travel.
Avalanche Problems
Wind Slabs
Snowfall and continual strong south to southwest wind have formed touchy wind slabs in lee terrain features. In areas sheltered from the wind, you may also find storm slabs that have developed, so assess for slab properties prior to jumping into consequential terrain features.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2.5