Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Possible
- Tamaño
- 4
Exec. Director Chad Brackelsberg stomped around mid Weber Canyon Sunday, finding mostly stable snow and great riding conditions. In the video above, Chad describes his findings whilst conducting a Propagation Saw Test (PST). His results as well as our collective observations and lack of avalanche activity suggest we're shifting towards more stable snowpack characteristics, but still remain in the "low probability/high consequence" realm. An oldie, but a goodie, Trent explains how to set up and interpret this test.
Here's the setup-
A persistent weak layer (PWL) of faceted, old, sugary snow near the ground is found mostly in mid and upper elevation terrain facing the north half of the compass. Remember- late December storms stacked up remarkable amounts of dense, heavy, water laden snow, coupled with very strong winds, bringing the weak layer to its tipping point. And while all of the snow since Christmas is a good thing that eventually heals this weak layer, it doesn't happen overnight. Sure, things are calming down, avalanche activity isn't off the charts, and it's been a few days since any significant slides have been reported. But the big red flag is that last weeks avalanches continue breaking on our early season problem child or, in snow-geek-speak... persistent weak layer (PWL). So, while conditions are slowly improving, I'd continue steering clear of any steep, wind drifted slope, especially those that harbor old October snow.
For now what makes this layer dangerous is:
- Once triggered, avalanches will break 3-5 feet and may be hundreds of feet wide
- It may not be the first person on a slope that triggers A LARGE, DANGEROUS avalanche, it may be the second, third, fourth, etc. who triggers it.
- Seeing tracks on a slope DOES NOT mean it's safe.
Here's the good news - This layer doesn't exist on south facing slopes which have excellent coverage, and soft creamy powder.
