Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
The likelihood of triggering a persistent slab avalanche is decreasing. The poor structure still exists, however, the snow grains are rounding. This process takes time. This problem is found on specific terrain features (i.e. shaded slopes above 7000'). There is a discrepancy within our forecast zone. This problem has become fairly unreactive in areas north and east of McCall. In areas near and within the West Mountain Range, the persistent slab problem (although stubborn), has been slightly more reactive. Although the likelihood has changed, triggering a large avalanche on weak snow near the ground is not impossible. The weight of a snowmachine is more likely to impact these weak layers than the weight of a person.
Additional Discussion: 2-4 inches of snow fell overnight with strong SW winds. This new snow fell on a melt-freeze crust. You can expect to encounter shallow new snow problems on this crust. In wind-loaded terrain, you may find shallow wind slabs of 6-8".