Avalanche Forecast
Regions: Coquihalla, Manning, Skagit.
⚠️ Avoid all avalanche terrain ⚠️
Widespread natural avalanches are expected as temperatures remain above mountain top for several days
Confidence
High
Avalanche Summary
Reports of avalanche activity have been limited. A notable size 2 persistent slab avalanche was observed in Manning Park and likely occurred over the weekend (photo below).
Continued activity is expected - with possible persistent slabs, widespread loose wet avalanches and cornice failures as warming continues.
Snowpack Summary
Expect to find moist or wet snow at all elevations except the highest north facing terrain. 30-50 cm of snow from the past week is rapidly settling over a variety of layers including a thin sun crust on south aspects.
There has been evidence of two persistent weak layers roughly 80 to 120 cm deep. The upper one is a thin layer of facets and crusts or surface hoar while the deeper one is facets above a thick crust. While we have not seen many reports of persistent slab avalanches in this region, these layers should not be trusted based on notable activity in neighbouring regions.
The warm temperatures are expected to increase reactivity of all buried weak layers, producing large natural avalanches.
Weather Summary
Thursday Night
Mostly clear. 15 km/h north ridgetop wind. Freezing level remains above 3000 m overnight.
Friday
Mostly sunny. 20 km/h northwest ridgetop wind. Treeline temperature +6 °C with freezing level climbing to 3400 m.
Saturday
Sunny. 20km/h east ridgetop wind. Treeline temperature +8 °C with freezing level steady at 3500 m.
Sunday
Sunny. 2- km/h southerly ridgetop wind. Treeline temperature +7 °C with freezing level sustained at 3300 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of strong sun.
- Avoid exposure to overhead avalanche terrain as temperatures increase.
- Cornice failure may trigger large avalanches.
Avalanche Problems
Persistent Slabs
While we have not seen widespread evidence of this problem, it will likely become reactive with the heat and sun. If triggered, very large and destructive avalanches are likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 2 - 3.5
Loose Wet
The snowpack will not have a chance to refreeze and gain strength overnight. Wet avalanches (loose or slab) are expected in any avalanche terrain but most likely on steep sun-exposed slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2