Avalanche Forecast
Regions: Boundary, East Stikine, Kispiox, Ningunsaw, Northwest Coastal, Northwest Inland, Stewart, West Stikine.
Natural avalanches are expected as new snow and wind stress the snowpack.
Avoid any terrain with overhead hazard, persistent weak layers are capable of producing very large avalanches.
Confidence
Moderate
Avalanche Summary
Several natural persistent slab avalanches were reported on Monday, failing on the March surface hoar. Several stepped down to deeper weak layers producing avalanches up to size 3.
We expect this activity to continue with rapid loading from new snow and wind on Wednesday.
Snowpack Summary
Storm snow will accumulate over wind affected surfaces at higher elevations, with deeper deposits expected in north facing terrain features. Older wind slabs likely still linger below, found on all aspects. Lower elevations will receive a mix of rain and wet snow.
Two layers of concern currently exist in the upper-mid snowpack. Surface hoar on a crust can be found 50 to 90 cm deep. And a layer of facets, surface hoar and/or a crust from mid-February is buried 70 to 120 cm deep.
The remainder of the snowpack is well consolidated with no current concerns.
Weather Summary
Tuesday Night
Cloudy with up to 10 cm of snow. 30 to 60 km/h southwest ridgetop winds, increasing overnight. Treeline temperature -8 °C.
Wednesday
Cloudy with 5 to 15 cm of snow, favouring coastal areas. 50 to 80 km/h southwest ridgetop wind. Treeline temperature -2 °C as freezing levels rise to near 1200 m.
Thursday
Cloudy with up to 5 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Friday
Cloudy with flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -2 °C as freezing levels rise to 1200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Minimize exposure during periods of heavy loading from new snow and wind.
- Avoid shallow snowpack areas, rocky outcrops, and steep terrain where triggering is most likely.
- Be aware of the potential for large avalanches due to buried weak layers.
Avalanche Problems
Persistent Slabs
New snow and wind will stress weak layers. Surface hoar and facets buried in the upper snowpack have produced recent avalanches. Large loads or step-downs could trigger the more deeply buried weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3
Storm Slabs
Fresh and reactive storm slabs will develop over the Wednesday. Expect deeper and more reactive deposits on north facing slopes. Storm slabs may step down to wind affected snow below, or buried weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2.5