Avalanche Forecast
Issued: Jan 8th, 2025 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
Avalanche Canada,
Avalanche Canada
New snow and wind are creating very dangerous avalanche conditions. Travel in avalanche terrain is not recommended.
Summary
Confidence
Moderate
Avalanche Summary
Observations have been limited by poor visibility during the storm. On Tuesday, natural storm slabs were observed up to size 3 in the alpine and size 2 below treeline. We expect similar natural avalanche activity to be ongoing through the storm on Thursday.
On Monday, north of Stewart, a vehicle triggered a size 1.5 persistent slab avalanche on a northwest aspect in the alpine.
Snowpack Summary
Another 15-30 cm of snow is expected by the end of the day Thursday, bringing storm totals to 30 to 70 cm. The new snow arrives with strong to extreme winds, particularly near Terrace, so significant wind transport is expected at upper elevations. Below 1200 m, the snow surface may be moist, wet or crusty.
The recent snow isn't expected to bond well where it sits on a layer of buried surface hoar, facets, or a thin crust.
A weak layer of surface hoar and facets overlying a crust is buried 60 to 120 cm deep in the southern parts of the region, and up to 200 cm deep in areas north of Stewart. If the new snow overloads this layer, causing it to fail, the resulting avalanches will be very large and destructive.
Weather Summary
Wednesday night
Cloudy with around 5 cm of snow. Southwest ridgetop wind increasing 20 to 50 km/h. Treeline temperature -2°C. Freezing level 1200 m near Terrace, 800 m near Stewart.
Thursday
Cloudy with 15 to 30 cm of snow. 70 to 100 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1200 m near Terrace, 800 m near Stewart.
Friday
Cloudy with 10 to 20 cm of snow. 50 to 70 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 800 to 1000 m.
Saturday
Cloudy. 30 to 40 km/h northwest ridgetop wind. Treeline temperature -5 °C. Freezing level valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
- Be aware of the potential for large avalanches due to buried weak layers.
- Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.
- Conservative terrain selection is critical; choose gentle, low consequence lines.
Problems
Storm Slabs
New snow and strong west winds are building reactive storm slabs. The highest danger will be on steep, leeward slopes below ridgetops.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A buried weak layer is being rapidly loaded by the new snow. Slabs failing at this depth will result in large and destructive avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 9th, 2025 4:00PM
