Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Wind slabs may be triggerable on a variety of aspects at upper elevations.
Wind slabs may step down to deeper layers, resulting in larger avalanches.
Seek out conservative, low consequence terrain.
WE have some uncertainty in the likelihood of persistent slabs, conservative terrain choices are the best defense.
Wind slabs may be triggerable on a variety of aspects at upper elevations.
Wind slabs may step down to deeper layers, resulting in larger avalanches.
Persistent weak layers of crust/facets or surface hoar are buried in the upper 250 cm of the snowpack. Signs of instability may not be evident. The best defence is choosing smaller, low-consequence terrain.
A few notable avalanches occurred over the weekend.
· A natural size 3 persistent slab was observed near Stewart. This avalanche might have initiated as a wind slab and then stepped down to the early February layer.
· A couple very large natural cornice falls were reported in the far north of the region. One of these cornices triggered a persistent slab on the slope below. Both were large enough that even without triggering a slab on the slope they were size 2.5 or greater.
Previous strong wind has created hard, pressed surfaces, wind slab, and scouring in exposed terrain. A new sun crust could be on or near the surface. Cornices are large and overhanging.
A layer of facets and/or surface hoar from earlier in March can be found 50 to 100 cm deep.
Several older persistent weak layers are buried up to 250 cm deep. While triggering these layers is trending toward unlikely, they present a low-probability, high-consequence problem.
Monday Night
Mostly cloudy. 2 to 4 cm of snow. 20 km/h south ridgetop wind. Treeline temperature -7 °C.
Tuesday
Mostly cloudy. 1 to 2 cm of snow. 20 km/h southeast ridgetop wind. Treeline temperature -6 °C.
Wednesday
Mix of sun and clouds. 1 to 5 cm of snow. 30 km/h east ridgetop wind. Treeline temperature -4 °C.
Thursday
Mix of sun and clouds. 1 cm of snow. 20 km/h southwest ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.