Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 2–3
While the storm has ended and the Avalanche Warning expired, conditions are still very dangerous. Triggering a large, destructive avalanche 2-4 feet thick is likely. Just yesterday, a skier was injured in an avalanche on an out-of-bounds run near the Warm Springs base of Bald Mountain. Skiers in Trail Creek NE of Ketchum experienced monster collapses and remotely triggered a large avalanche from a low-angle ridgeline. These are clear indications that we're nowhere near being out of the woods.
The weekend storm walloped an early-season snowpack with multiple persistent weak layers. The result was predictable, but impressive nonetheless. At least three houses were hit, the Wood River in Hailey was temporarily blocked by an avalanche, and several very large avalanches hit and blocked the Warm Springs road—one damaging a structure and vehicle. For more details, read the Forecast Discussion below.
Conservative terrain choices are essential to staying safe in the backcountry. If you trigger an avalanche, it could be large enough to be unsurvivable. Steering clear of avalanche terrain and areas exposed to steeper slopes above is the only way to avoid this problem.
ADDITIONAL DISCUSSIONThe recent storm was accompanied by S-SE winds that blew strongly at times. Drifts and slabs that formed in wind-exposed terrain during the storm may remain sensitive. This problem pales in comparison to the persistent slab problem described above. If you trigger a wind slab, it's likely to "step down" into more deeply buried weak layers and produce a much larger avalanche.
(12/11/2022) This large avalanche occurred just outside of the ski area boundary on Bald Mountain. The human pictured is 6 feet tall. The crown was 3-4 feet thick. It failed on the layer of weak, faceted snow that is widespread in our forecast area. This slope faces NW at 8,800'.