Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
The tally of generally small human triggered avalanches on Saturday keeps growing. While not all of these slides suggest they failed on older persistent snow grains, a few certainly do. These include widely propagating slides, long shooting cracks, and audible whumpfs. So far, most of the avalanche activity seems isolated to wind loaded slopes, but that may change as temperatures warm and more snow falls. This won’t be an easy problem to manage or nail down. Certain slopes might not slide, while others could trigger very easily. Avalanches that do release could break widely or even trigger remotely. Ultimately, all steep open terrain is in question, particularly above 4000 ft.
You can use small slopes, hand pits, and snowpack tests to look for and assess these grains, but they can’t tell you any particular area is safe. The best thing you can do is keep it simple.
Winds were cranking at the Pass on Saturday and don’t appear to let up. Even if the persistent weak layers aren’t a problem, wind loaded slopes certainly are. Steer around firm pillow-like slabs.
(2/21/2026)
An unintentionally triggered, widely propagating avalanche from 2/21. N, 5500ft. Its unconfirmed, but this slide may have failed on older persistent grains.
Photo: NWAC