Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Very Likely
- Size
- 4
The more than 50 recent avalanches failing on the persistent weak layer (PWL) over the past four days are a stark reminder that this problem is a significant concern, particularly in the most suspect areas—steep, mid and upper elevation terrain features where the PWL exists.
Several feet of snow, containing nearly 4 inches of water and accompanied by days of strong winds, have overloaded our weak and faceted snowpack. While all this snow could eventually help heal the PWL, for now, it has only complicated the situation. What once had no slab has transformed into a 1-4' slab across the range in a matter of days, with potentially deeper slabs in wind-drifted areas. These are deep and deadly avalanches.
What to do:
- Avoid being on, underneath, or adjacent to slopes steeper than 30°.
- Remember that avalanches can be triggered remotely, from a distance, or even from below.
The clear skies and appealing riding conditions can create a false sense of safety, but the avalanche danger remains very real. Opt for lower-angle terrain for safer riding. The conditions are prime for potential avalanche accidents, and our top priority is ensuring that everyone makes it home safely at the end of the day.
A large avalanche along Culter Ridge at 9100' on a NE aspect that appeared to run naturally during the last cycle. This is the type of avalanche you could expect to see on the PWL. Photo: Kaufmann
