Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Recent snow and moderate northwest wind are building fresh wind slabs above 1400 m in direct lee features like the downwind side of ridges, peaks, and terrain breaks.
Sun and daytime warming can quickly change snow conditions. Avoid steep slopes if the snow is moist, and stay well clear of cornices, which may weaken and threaten slopes below.
Recent snow and moderate northwest wind are building fresh wind slabs above 1400 m in direct lee features like the downwind side of ridges, peaks, and terrain breaks.
A persistent weak layer is buried 1 - 2 m. Recent reports are pointing to this layer gaining some strength with facets rounding and the crust breaking down.
Clear skies will allow for strong solar radiation to impact recent storm snow for the first time. Watch for surface snow becoming moist and back off steep slopes while solar radiation is intense.
No recent reports on Wednesday.
On Tuesday a large, size two avalanche was triggered by a snowmobile. The release was in an open alpine feature and may have involved a weak layer down 75 to 150 cm. The field team observed a recent natural (size 1.5) wind slab avalanche that looked to be 24 to 48 hours old.
Sunny clear skies will likely initiate a wet loose cycle as recent storm snow sees sun for the first time.
Sunny skies and continued northwest winds are creating variable surface conditions.
Above 1400 m, up to 20 cm of recent storm snow has been redistributed by strong northwest winds, forming new wind slabs. This overlies wind-affected surfaces in exposed terrain and faceted snow in sheltered terrain.
At treeline and below, roughly 5 to 7 cm of dry snow overlies moist and/or refrozen surfaces. Below 700 m, the snowpack is becoming isothermal. On sun-facing slopes, the surface snow is becoming moist.
A thick crust with faceted snow from late January can be found at a wide range of depths, from 75 to 150 cm.
Wednesday Night
Clear skies. 20 km/h northwest ridgetop wind. Treeline temperature -3 °C.
Thursday
Mostly sunny. 20 km/h northwest ridgetop wind. Treeline temperature -2 °C.
Friday
Mix of sun and clouds. 20 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 1500 m.
Saturday
Mostly sunny. 10 km/h southwest ridgetop wind. Treeline temperature 3 °C. Freezing level 2000 m.
More details can be found in the Mountain Weather Forecast.