Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 4
Various layers of weak, faceted snow and depth hoar are present on mid and upper elevation aspects facing west through north and southeast. Over this past week, several natural and human-triggered avalanches failed in these persistent weak layers, now buried 2-4' deeply. Today's rapid loading of new snow and wind-drifted snow may be enough to again overload these deeply-buried weaknesses, with avalanches breaking down up to 5' deep and over several hundred feet wide. You may not get any warnings - such as collapsing or cracking - of these instabilities until you hit the right spot on the slope and trigger a large, dangerous, and likely unsurvivable avalanche.
The best advice is to avoid being on or underneath slopes steeper than 30° on these aspects at the mid and upper elevations where this persistent weak layer is present.
The video below is from the remotely-triggered slide on Tuesday in Days Fork that was 3' deep and failed in the buried persistent weak layer.
AVALANCHE TREND: INCREASING