Avalanche Forecast
Issued: Feb 4th, 2025 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
Avalanche Canada,
Avalanche Canada
New snow overlies a prominent weak layer in sheltered areas at treeline and below. Avoid areas where snow feels stiff or slabby.
Check out the Forecaster Blog Keeping a Conservative Mindset.
Summary
Confidence
High
Avalanche Summary
On Monday, a few human-triggered size 1 wind slab avalanches were reported in northerly alpine and treeline features. Avalanche control produced several explosive-triggered persistent slab and dry loose avalanches, up to size 1.5.
A size 2 natural wind slab avalanche was observed in northeast-facing alpine terrain.
We expect unconsolidated snow will remain reactive to skier traffic on Wednesday in steep terrain. Carefully manage sluffing in steep terrain.
Snowpack Summary
Storm snow totals range from 30 to 50 cm, with deeper deposits in wind-loaded areas. The new snow is bonding poorly to old surfaces, which include melt-freeze crusts on sun-exposed slopes, surface hoar or facets on shaded slopes, and wind-affected snow at higher elevations.
A weak layer of surface hoar of facets is buried, 30 to 60 cm deep. Where this layer is preserved it may be reactive to human triggering.
A weak layer of facets from early December is buried 60 to 120 cm deep.
The base of the snowpack consists of a thick crust with facets or depth hoar in many areas.
Weather Summary
Tuesday Night
Partly cloudy with a chance of flurries, 0 to 1 cm of snow. 10 to 15 km/h variable ridgetop wind. Treeline temperature -20 °C.
Wednesday
A mix of sun and cloud. 10 to 25 km/h west ridgetop wind. Treeline temperature -16 °C.
Thursday
Mainly sunny. 10 to 15 km/h northwest ridgetop wind. Treeline temperature -15 °C.
Friday
Mainly sunny. 5 to 15 km/h northwest ridgetop wind. Treeline temperature -15 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
- Avoid freshly wind-loaded terrain features.
- Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
- Keep in mind that human triggering may persist as natural avalanches taper off.
Problems
Persistent Slabs
A weak layer of surface hoar and facets or a crust exists 30 to 60 cm down. This layer is reactive to human-triggering where a slab has developed above it. Watch for signs of instability: whumphing, shooting cracks and recent avalanches.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
With plenty of snow available for transport watch for localized winds building fresh reactive wind slabs in lee terrain features. Windslab are most reactive during formation.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 5th, 2025 4:00PM
