Avalanche Forecast
Regions: Coquihalla, Harrison-Fraser, Manning, Skagit.
As warm temperatures and sun heat up the snowpack, uncertainty around buried weak layers is best managed through conservative terrain choices.
Confidence
Moderate
Avalanche Summary
Recent avalanche activity has been mostly loose wet out of steep solar aspects, size 1-2.
Evidence of natural avalanches from the past weekend's storm is still visible throughout the region, with numerous very large (size 3.5 to 4) persistent slabs with impressive crowns (100 to 200 cm) in the Manning region.
Snowpack Summary
20 to 30 cm of recent snow sits over a crust, and is becoming moist or wet with warm temperatures and sun. At upper elevations, previous strong wind has redistributed surface snow, building wind slabs and cornices in lees.
A weak layer of facets and/or surface hoar is buried 50 to 120 cm deep. Large avalanches ran on this layer last weekend and it continues to give easy results in snowpack tests. We remain wary of it especially during these warm temperatures.
A crust from December, buried 1 to 2 m deep, has been observed to be breaking down.
Below 1300 m, the snowpack is saturated and disappearing quickly.
Weather Summary
Friday night
Clear. 10 to 20 km/h southwest ridgetop wind. Treeline temperature +5°C. Freezing level rising to 3200 m.
Saturday
Sunny. 20 to 30 km/h south ridgetop wind. Treeline temperature +6°C. Freezing level 3000 m.
Sunday
Mostly cloudy with 1 to 4 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature 0°C. Freezing level 1600 m.
Monday
Sunny. 20 to 40 km/h northeast ridgetop wind. Treeline temperature 0°C. Freezing level 1500 m.
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.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
- In times of uncertainty, conservative terrain choices are our best defense.
Avalanche Problems
Persistent Slabs
Large avalanches were observed on buried weak layers during the storm last weekend. Warm temperatures have potential to reactivate them this weekend.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 2 - 3
Loose Wet
Warm temperatures and sunshine will destabilize the surface snow on sun-exposed slopes.
Aspects: South, South West, West.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2
Wind Slabs
Wind slabs may remain sensitive to rider triggers in lee terrain features, especially at higher elevations. Small wind slab releases may step down to weak layers in the upper snowpack to produce larger, more destructive avalanches.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2.5