Avalanche Forecast
Regions: Tutshi, Wheaton, White Pass East, White Pass West, Yukon.
Stick to conservative terrain free from overhead hazards. A reactive weak layer in the region is best managed by choosing simple terrain, and avoiding freshly wind-loaded slopes.
Confidence
Low
Avalanche Summary
On Tuesday, the field team observed two old size 2 wind slabs from the highway. We expect that natural wind slab avalanches likely occurred on Sunday and Monday during periods of strong wind.
Last Wednesday, a snowmobile remotely triggered a size 3 persistent slab from 100 m away near Bryant Lake. It was triggered from flat terrain at the col on an ENE aspect at 1500 m (MIN report).
Snowpack Summary
30-50 cm of settling storm snow from the last week can be found in sheltered terrain. Exposed terrain has been heavily wind-affected.
A weak layer of facets and a crust from early December is buried 50 to 100 cm deep. This layer exists on all aspects up to around 1700 m. This layer has shown recent reactivity, and we expect it to remain sensitive to human triggering.
Check out this recent ACMG Mountain Conditions Report for more on the persistent weak layer problem.
Weather Summary
Tuesday Night
Cloudy with light snowfall 2-4 cm. 30 to 50 km/h south ridgetop wind. Treeline temperature -6 °C.
Wednesday
Cloudy with 4-8 cm of snowfall. 40 to 60 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Thursday
Partly cloudy with flurries. 30 to 50 km/h west ridgetop wind. Treeline temperature -4 °C.
Friday
A mix of sun and cloud. 30 to 50 km/h west ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for large avalanches due to buried weak layers.
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.
Avalanche Problems
Persistent Slabs
A weak layer of facets and a crust down 50 to 100 cm has produced very large avalanches over the past week. Remotely triggered avalanches and wide propagations remain possible.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 2 - 3.5
Wind Slabs
Recently formed wind slabs are expected to remain reactive to human triggering. New snow with strong winds on Wednesday may further add to these slabs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5