Avalanche Forecast
Regions: Coquihalla, Manning, Skagit.
Stormy weather returns ! Fresh and reactive wind slabs will be a concern.
Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and steep terrain.
Confidence
Moderate
Avalanche Summary
On Monday, a large wind slab avalanche (size 2) was triggered by mountaineers on a southerly slope of Markhor Peak. It propagated 20 m wide and ran on a buried hard sun crust.
Thanks for sharing your observations via the MIN if you are going out into the backcountry.
Snowpack Summary
10 to 15 cm of new snow and strong wind is expected by Thursday afternoon, forming touchy wind slabs. This overlies wind-affected snow in lee terrain at upper elevations and moist, heavy snow or a melt-freeze crust on southerly slopes, especially at lower elevations.
A supportive crust is found 60 to 80 cm deep on all aspects except on high, north-facing alpine terrain, and the recent settling snow is bonding well to it.
A weak layer of facets and surface hoar from February is now 90 to 150 cm deep and a layer of facets and surface hoar from late January is 130 to 190 cm deep. No recent notable test results have been seen on these layers.
Weather Summary
Wednesday Night
Cloudy with 5 to 10 cm of new snow. 30 to 50 km/h south ridgetop wind. Treeline temperature -6 °C. Freezing level 800 m.
Thursday
Cloudy with 5 to 10 cm of new snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.
Friday
Cloudy with 15 to 25 cm of new snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.
Saturday
Cloudy with up to 5 cm of new snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs are most reactive during their formation.
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Cornice failures could trigger large and destructive avalanches.
Avalanche Problems
Wind Slabs
New snow and wind will create fresh wind slabs. Expect slab size and sensitivity to triggering to change drastically as you move into wind-exposed terrain.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2