Avalanche Forecast
Regions: North Columbia.
Strong northeasterly winds have reverse loaded slopes below alpine ridgetops. Recently formed wind slabs may be reactive to human triggers.
Use high points in the terrain such as ridges or ribs to avoid areas of wind-loaded snow.
Confidence
High -
Weather Forecast
Tuesday night: Clear / Moderate east wind / Low of -19 / Freezing level valley bottom.
Wednesday: Mix of sun and cloud / Light east wind / High of -6 / Freezing level valley bottom.
Thursday: Mix of sun and cloud / Light east wind / High of -4 / Freezing level 800 m.
Friday: Mostly sunny / Light west wind / High of -3 / Freezing level 1100 m.
Avalanche Summary
A very large (size 4) persistent slab avalanche triggered by a massive cornice failure on a northeast aspect was reported north of Revelstoke in the Selkirk mountains on Monday.Â
The triggering of this avalanche was only possible with an extremely large load and is not representative of the general conditions of the region as a whole.
Snowpack Summary
10-20 cm of recent snow sits on a melt-freeze crust that exists on all aspects to at least 2200 m and up to mountain tops on solar aspects.
Recent strong northeasterly winds have formed wind slabs on lee aspects below ridgetops.
The prominent layer in the upper snowpack is a melt-freeze crust down 50-80 cm.
Cornices are very large and exposure to slopes beneath them should be minimized, especially if the weather is sunny, warm, or windy.
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
- Caution around slopes that are exposed to cornices overhead.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Avalanche Problems
Wind Slabs
Recent strong northeasterly winds have formed wind slabs on lee aspects below ridgetops.
Use high points in the terrain such as ridges or ribs to avoid areas of wind-loaded snow.
Aspects: North, South, South West, West, North West.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 1.5