Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2
Any slope harboring old snow that fell in October should be avoided because it will likely produce an avalanche. The old October snow became weak and faceted. It is now a persistent weak layer on which many avalanches have occurred. Yesterday this layer was collapsing and whumpfing as Trent and I skied in Days Fork. This layer is thickest and easiest to find on any northerly facing slope. We found it on E facing slopes and even on SE facing slopes above 9500 feet.
With additional loading overnight, this layer will likely produce avalanches today if you get on a slope steeper than 30 degrees.
HEADS UP - More snow and increased S/SW winds will come this afternoon. These southerly winds will drift snow onto northerly facing slopes which are ones with the weakest and most unstable snow. Depending on how much snow falls tonight, avalanches could occur naturally tomorrow. I would also expect that you could trigger them remotely which means you can trigger them from some distance away.