Wind Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 1–2
With moderate to strong winds out of the SW and more snow coming in, wind slabs will continue to build overnight and Thursday. Wind slabs can be tricky. It is easy to gain confidence in lee terrain when you don't see any signs of unstable snow only to find that a slight change in aspect has reactive wind slabs. Stay diligent and keep monitoring the conditions on Thursday. Checking on the depth of wind deposited snow is a key observation. Some slopes will have shallow wind slabs while isolated pockets of terrain can accumulate a lot more wind blown snow. Deeper wind slabs can lead to larger avalanches. Hand sheer tests and ski pole probing are good methods to check for depth of wind slab.
Look for wind slabs in the usual suspect terrain such as below ridges and high points. Slopes can also become 'crossloaded' as the wind wraps around a slope.
Previous avalanches and cracking in wind deposited snow are indicators that wind slab avalanches can occur. Utilizing small safe test slopes are good ways to check for reactivity in the slab.
With strong winds in the forecast, be cautious in areas that you may typically think of as 'below treeline', especially in clearings and areas of sparse or dead trees. These areas can be exposed to wind blowing snow and wind slabs can develop.
(3/27/2024)
Skier triggered wind slab avalanche on Wednesday at the top of the Tumalo bowl (east aspect, near treeline). This was in a pocket that catches blowing snow from the SW winds. The crown was 15-20 cm (6 - 8"). Size D1 (small).
Photo: Aaron Hartz