Avalanche Forecast
Regions: North Shore, Powell River, Sky Pilot, South Coast, Tetrahedron.
As precipitation piles up, danger increases with it. With storms this dramatic, it is a great time to avoid avalanche terrain until things calm down.
Confidence
Moderate
Avalanche Summary
Numerous size 1 skier triggered storm and wind slab avalanches were reported over the weekend, including in the Powell River area.
These avalanches were typically at treeline or above on north and east aspects. Reports indicate that the recent storm snow is not bonding well to the underlying weak layers as these avalanches were easy to trigger.
Snowpack Summary
New snow falls on 15 to 25 cm of snow from the weekend, which fell with southerly wind, forming deeper slabs on northerly aspects. In sheltered terrain this new snow may overlie soft, faceted snow or surface hoar. In exposed terrain it will overlie a sun crust or wind-affected snow.
At lower elevations a new crust likely exists below the storm snow.
A late-January weak layer (hard crust, facets, or surface hoar) is buried 80 to 120 cm deep, this layer could become reactive the more the precipitation adds load on it.
The lower snowpack is strong and bonded.
Weather Summary
Wednesday Night
Cloudy with 20 to 50 mm of mixed precipitation. 25 to 40 km/h southeast ridgetop wind. Freezing level 1300 m.
Thursday
Cloudy with 5 to 10 mm of mixed precipitation. 15 to 30 km/h southwest ridgetop wind. Freezing level 1200 m.
Friday
Cloudy with 20 to 50 mm of mixed precipitation. 40 to 70 km/h southwest ridgetop wind. Freezing level 1500 m.
Saturday
Cloudy with 50 to 100 mm of mixed precipitation. 40 to 70 km/h southwest ridgetop wind. Freezing level 2000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Closely monitor how the new snow is bonding to the old surface.
- Approach steep and open slopes at and below treeline cautiously, as buried surface hoar may exist.
- Be aware of the potential for large avalanches due to buried weak layers.
- A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
Avalanche Problems
Storm Slabs
The recent storm snow is not bonding well to the underlying weak layers. This problem is most prevelant at treeline and above in wind loaded features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2
Loose Wet
Warming temperatures combined with precipitation will increase likelihood of wet loose avalanches.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Very Likely
Expected Size: 1 - 1.5
Persistent Slabs
Increased load on the January drought layer may cause it to become active again. Small storm avalanches may step down to this layer.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1.5 - 2.5