Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 3
We had roughly 16 days of clear and cold weather in November, where our snowpack became weaker each day/night, creating a layer of weak faceted snow called a Persistent Weak Layer. This weak layer was buried on the 27th of November on almost all aspects and elevations throughout the mountains. Strong southerly winds and new snowfall over the past few days have overloaded this persistent weak layer, and we are now seeing deep and dangerous avalanches.
These avalanches are not to be taken lightly as they will break 1-3' feet deep and up to 300' wide (perhaps wider). These avalanches can be triggered from a distance (remotely) and can travel long distances downhill into the flats.
Video: Greg Gagne in Powder Mountain Backcountry.