Wind Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Possible
- Taille
- 1–2
Watch for fresh wind slabs forming on Thursday. If you see blowing snow, avoid slopes below.
There is potential for large avalanches to be triggered, particularly in wind-loaded areas near ridgetops.
Watch for fresh wind slabs forming on Thursday. If you see blowing snow, avoid slopes below.
A widespread crust with weak crystals overtop is buried 30-70 cm deep. This problem is specific to areas where a cohesive slab has formed over the layer, such as wind-loaded lee features.
Our field team observed a few small wind slabs in the Sinclair area on Wednesday, and several large slab avalanches up to size 2 in the Telkwas on Monday. These all occurred mostly on wind-loaded leeward slopes, with the larger ones failing on the December crust (for more details click the photos below).
Looking forward, we expect both wind slabs and persistent slabs to remain a problem over the coming days.
5 to 10 cm of soft snow blankets harder wind-affected surfaces in the alpine and at treeline. Recent and forecast southeast winds are expected to blow any available soft snow into fresh wind slabs on leeward north through westerly slopes.
Deeper pockets of soft snow should still be able to be found in sheltered terrain and in the trees.
A significant weak layer can be found across the region, buried 30 to 70 cm, depending on wind loading patterns. This layer is made of weak facets overlying a hard crust. We expect this layer to persist as a problem as it continues to be buried even deeper.
The remainder of the snowpack is well settled and bonded.
Wednesday night
Clear. 30 km/ east ridgetop wind. Treeline temperature -18 °C.
Thursday
Clear, with increasing cloud in the afternoon. 30 to 40 km/h southeast ridgetop wind. Inversion developing; treeline temperature -16 °C.
Friday
A mix of sun and cloud. 25 to 30 km/h south ridgetop wind. Inversion; treeline temperature -15 °C, alpine -10 °C.
Saturday
Mostly sunny. 10 to 20 km/h south ridgetop wind. Inversion; treeline temperature -15 °C, alpine -10 °C.
More details can be found in the Mountain Weather Forecast.