Avalanche Forecast
Regions: Tutshi, Wheaton, White Pass East, White Pass West, Yukon.
Natural avalanches are likely in the White Pass area as strong winds and new snow stress a weak snowpack.
Avoid avalanche terrain and any overhead hazard.
Confidence
Moderate
Avalanche Summary
Natural and human triggered avalanches are expected as Mondays storm will stress a weak snowpack.
On Friday riders triggered a slab with a 1 m crown depth in the Big Y. On Wednesday, a snowmobile remotely triggered a size 3 persistent slab on the December facet/crust layer from 100 m away near Bryant Lake. It was triggered from flat terrain at the col on an ENE aspect at 1500 m.
Snowpack Summary
By Monday afternoon 20 cm of wind affected storm snow likely has fallen at White Pass with deep deposits expected in wind loaded terrain. This will fall over up to 40 cm of heavily wind affected snow. Strong southwest winds will continue to redistribute snow where it is available for transport.
A weak layer of facets and a crust is buried 50 to 100 cm deep and continues to be reactive with the new load from snow and wind.
Total snow depths are around 160 to 190 cm at treeline.
Check out this recent conditions report for more on the persistent weak layer problem.
Weather Summary
Sunday Night
Cloudy. Up to 5 cm of snow. 80 gusting to 100 km/h southwest ridgetop wind. Treeline temperature -8°C.
Monday
Cloudy, possible afternoon sunny periods. 5 to 15 cm of snow, favouring White Pass. 60 to 80 km/h southwest ridgetop wind. Treeline temperature -6.
Tuesday
Mostly cloudy. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -9 °C.
Wednesday
Mostly cloudy. 50 to 70 km/h southwest ridgetop wind. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
- Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Persistent Slabs
A reactive weak layer of facets and a crust is buried 60 to 100 cm deep. Remote triggering from afar is possible and it will produce large and destructive avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 2 - 3.5
Wind Slabs
Reactive wind slabs may linger from the previous storm, and fresh wind slabs are expected to form with new snow and wind on Monday. Give wind loaded slopes time to settle and bond.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1.5 - 2.5