Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
In the last week observers and forecasters have been consistently finding weak snowpack structure in the snowpack throughout our forecast area. Column tests on northwest, north, and northeast facing terrain have been consistently revealing poor stability in the mid and lower layers of our snowpack. The weak layers are uncohesive faceted or "sugar" snow that are located deep in the snowpack. The weak layers we are concerned about are less than 4" thick and rest atop a firm crust which makes for an ideal sliding surface. Precariously perched on top of this crust/facet combo is a 2' - 3' slab of snow waiting to take an unsuspecting rider for a harrowing and potentially lethal ride down the mountain. Also in the last week, rider triggered avalanches and collapses have occurred both in our forecast area and just outside our forecast area. These are glaring red flags that should not be ignored when considering recreating on terrain steeper than 30 degrees today. I encourage anyone going into the mountains today to take a look at the observations posted in the last week on this website.
(12/6/2022)
This snowpit was dug on Tuesday on a northwest facing slope at 7500' . I performed an extended column test that failed (full propagation) about 2' down. The week layer was about 3" thick and made up of facets or uncohesive sugar snow. ECTP15
Photo: TG