Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 4
Persistent weak layers of faceted snow are still lurking in the snowpack and are now buried quite deeply. People continue to report lots of collapsing, mainly in rocky areas which is a red flag.
Many slopes avalanched during big storms in mid January on facets from dry weather in late December as well as old faceted layers of November snow. A complex mix of layers remains in most avalanche starting zones. Additionally, a few weak layers formed during very warm weather at the end of January that were buried by the recent storms. I found a layer of buried surface hoar (photo below) above Smith and Morehouse Reservoir on Friday. Yesterday on the north slope of the Uintas near Boundary Creek, Ted easily found these layers when digging a snow pit and his "shovel just plunged into quite weak sugary faceted snow." Nearby Mike Wessler reported loud, booming collapses.
Overall, these weak layers are gaining a little strength each day and will become dormant soon, but I'm not ready to trust them with my life yet. Steep, rocky slopes are the most likely places to trigger a hard slab avalanche that could break 3-5 feet deep.