Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Possible
- Dimensione
- 1
There are two distinctly different persistent weak layers we're watching. One is the old PWL of November/December snow that last caused avalanches about a month ago. It is dormant for now and could stay that way for the rest of the season.
The second PWL possibly formed early in the week. Dave, Sam, and I easily found it yesterday in Corkscrew glades, but it only has about 6" of snow on top of it and was stubborn in our stability test. However, it did produce one collapse with a shooting crack as we crossed a subtle ridge feature where localized winds had drifted a little bit of snow. We confidently skied steep terrain where the powder was soft and winds had not moved any snow. The slide Eric found on Wednesday shows that we can't let our guard down.
Now it's tricky. With the old PWL near the ground going dormant, I would be stepping out into bigger terrain. However, I'd be checking the top foot of the snowpack looking for this most recently PWL. We suspect that it may exists even in alpine terrain because winds have been mostly light since it formed and was buried. If I were to find this weak layer, I would only be worried about it where winds drifted some snow - which may not be totally obvious.