Persistent Slabs
- Alta quota
- Limite del bosco
- Sotto il limite del bosco
- Probabilità
- Likely
- Dimensione
- 3
It is very simple – steep slopes with old snow are dangerous. Any slope that was white with snow before Thanksgiving has weak, sugary facets near the ground. And now these slopes are loaded with new snow, they are continuing to produce avalanches 1 to 3 feet deep. Slides are being triggered from a distance and from on slope. Unfortunately, most slides are running in the upper layer of the facets, above the October rain crust, and not cleaning out lower facets or crusts.
These old faceted snow layers will remain a dangerous weak layer all week and will become even more reactive the next time it snows.
Here's a look Drew took of the snowpack at 8,500' on a north facing slope in the Provo area mountains, with the facets at the bottom. The weak facet layer depth will increase with elevation.