Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
New snow accumulations and very strong W/NW winds have built slabs of wind-drifted snow across middle and upper elevations. The bulk of precipitation fell during the overnight hours, so expect peak sensitivity in the morning. These slabs will be thicker, denser, and more consequential above 6000 ft. Look for these slabs on the downwind sides of ridges & canyons, below cornices, and near the top of confined features like chutes or gullies. This storm came with strong west wind speeds in the 35-50 mph range, so this may have created irregular loading patterns, and you may find these slabs further down slope or even on mid-slope convexities.
There should be plenty of clues, such as blowing snow or wind-textured surfaces, to help you identify where slabs have formed. Pay attention to stiffer snow surfaces and shooting cracks as obvious signs that slabs are resting uneasily. These slabs may range from soft to hard, and could break above you in heavily loaded upper elevation terrain. You can significantly reduce your exposure to this problem by sticking to wind-sheltered terrain, less than 35 degrees.
In some isolated, steep terrain, triggering small storm slabs or dry loose may be possible.
(12/26/2025)
Wind drifted pockets showed signs of reactivity on Friday. These observations should help you avoid wind-loaded start zones.
Photo: Joe Dellaporta