Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2
In my outing into the south fork of Provo Canyon yesterday, we found a similar snowpack as that in the central Wasatch. Old weak snow from October exists in the shady terrain above about 8500', but the overall trend is toward stabilization.
Stabilization can be slow. Our old friend and colleague and now Colorado forecaster Jason Konigsberg delivered a presentation in Innsbruck Austria looking at the numbers of human triggered persistent slab avalanches after a loading event. In a nutshell, he found that 84% of the avalanches were triggered within three days of the event while 93% of the avalanches were triggered within 7 days of the loading event. His study involved data from 2011-2018 looking at just over 1800 avalanches. His excellent paper can be found on the Montana State University International Snow Science Workshop proceedings directory here.