Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 3
A variety of persistent weak layers are still being found on mid-elevation and upper elevation west-north-east facing slopes and on upper elevation southeast facing aspects. These buried weak layers are variable and make for a complex problem. Thinner, rockier spots, and areas that avalanched earlier in the season are more likely to be places where you could trigger an avalanche failing on a buried layer of facets. This is most likely what we saw on this east facing slope (9,600') on Ant Knolls in the Northern Provo Region on Saturday, February 22. There are also avalanches being triggered within the new/old snow interface that are reacting more like a persistent weak layer avalanche in the mid-elevations and in some cases the only way to identify this weak layer is to get your shovel out, dig, and perform some sort of stability test. The last avalanches failing on a layer of weak buried facets in low elevation north facing terrain was on Thursday, February 20th in Summit Park, and on the southerly facing slopes the last reported persistent weak layer avalanche was in Little Cottonwood Canyon on Friday, February 21, 2025. While we have removed the persistent weak layer problem from the lower elevation terrain there is still a chance of an isolated human triggered avalanche failing into buried facets near the ground. If you hear any signs of collapsing at any elevation or aspect then find a lower angle slope to travel on or underneath.
We are not done with this buried persistent weak layer quite yet and as much as the mindset in late February typically turns to open-season, it's not that type of season. Give this snowpack some time to settle into its spring coat.
Photo (Shea) of a human triggered avalanche on Ant Knolls