Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
West and northwest winds have made quick work of crafting drifts and loading leeward pockets of terrain on south and east aspects near and above treeline. Today, finding instabilities on or near wind loaded features, such as ridgelines, sidewalls of chutes and gullies, or convex slopes, won't be difficult. Wind deposits often present themselves as lens-shaped, or dune-like, with rippled or wavy snow texture. Blowing snow and cornices will point you in the direction of wind loading.
Yesterday, wind lips and cornices were easily triggered, causing subsequent avalanches on the slopes beneath. While relatively small (<D1), this feedback illustrates the potential on a larger scale. With dry snow in the mountains, cold temperatures, and moderate wind speeds, the sensitivity of the problem will likely increase with the incoming storm. Stay tuned for red flags of avalanche danger and heed caution to steep, exposed terrain that displays signs of wind effect. Seek avoidance of this problem by traveling on windward aspects, scoured surfaces, or slopes less than 30 degrees.
Cornice collapse and subsequent avalanche on a leeward slope above treeline in the Old Ski Bowl, easterly facing
Photo: Eric Falconer