Wind Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Likely
- Taille
- 1–2
As more snow comes in overnight and Friday wind slabs will continue to build and avalanches will have the potential to be large. Remember that the wind can deposit snow many times deeper than the storm accumulation. Wind slabs are most sensitive to triggering when they are fresh.
Steep and convex terrain at and below ridge tops are the suspect places to trigger a wind slab but be cautious on any terrain feature that has accumulated blowing snow. As wind moves snow across open slopes, gully features in particular can become 'cross loaded' and filled in with new wind slabs. There can be a lot of variability associated with this problem; some lee slopes will have shallow windslabs while other slopes will collect a lot more blowing snow creating much deeper slabs.
There may be isolated pockets of weak faceted snow on steep north facing slopes under the new storm snow. Avalanches initiating on or stepping down to weak sugary snow may propagate wider and run farther than usual.
Cracking in the wind deposited snow and recent avalanches are good indicators that you can trigger an avalanche, but remember we don't always get that feedback even when unstable snow exists. Wind slabs can be avoided by sticking to sheltered areas or slopes that have been scoured by the wind.
Use carefull evaluation in areas of sparse trees, clearings, and sections of dead forests. Open areas 'below treeline' can get enough blowing snow to create wind slabs.
(3/13/2025) Photo: Aaron Hartz
On Thursday, an intentional cornice drop triggered a size 1 wind slab on Ball Butte. East aspect, near treeline.
