Wind Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1–2.5
Yesterday, strong southwest wind and snowfall rates of up to an inch an hour built reactive wind slabs by early afternoon. Public observers and our forecast team triggered avalanches on leeward aspects and wind loaded features. Most of these triggers occurred remotely from a considerable distance and is good reason to be aware of steep, wind-loaded slopes above you. Over the last 12 hours, wind and snow accumulations have continued and will endure throughout the day. You are likely to find areas of wind-drifted snow on leeward, W-NW-N-NE-E aspects, especially near ridges and rock outcroppings. Backcountry travellers should also be heads up to a different style of wind loading: cross-loading. Cross-loading occurs when terrain features, such as gullies or stands of trees, perpendicular to the wind allow for transported snow to collect into drifts. Carefully evaluate the snowpack before committing to avalanche terrain and be vigilant for signs of instability: recent avalanches, shooting cracks, collapsing, and blowing snow.
Visual depiction of wind loading and cross-loading dynamics
Photo: Illustration from Allen & Mike’s Avalanche Book by Allen O’Bannon and Mike Clelland (Falcon Guides).