Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Likely
- Tamaño
- 2–3
Over the past week, four riders have been caught and carried — some partially or fully buried. The weak layer that produced those avalanches is just as sensitive today. Let that reality guide your decisions.
If you poke this bear, you are likely to trigger a 2–3 foot deep avalanche on northwest through southeast aspects. Many slides are being triggered remotely, and even low-angle or atypical start zones are releasing. Take note of collapsing and cracking, but you don’t need additional red flags to confirm how dangerous this snowpack is — assume steep terrain will slide, and keep in mind that even a small slope could release and bury you deeply in a terrain trap (gully, road, etc).
The only way to manage this problem is to avoid it. Low-angle slopes with no overhead hazard will have excellent riding conditions. You could also consider south and west aspects where we haven’t seen persistent slab activity — keeping in mind that recent snow and wind add some uncertainty to those slopes.
Dry Loose:
Steep slopes will sluff the new low-density snow today. If you are traveling on solar aspects to avoid the persistent slab problem, you’ll need to manage this. They won’t be large, but could knock you off your feet in a place you don’t want to fall.
Large, consequential avalanches don't always have to start below a ridgeline (though there is one of those in this photo!). The slide here on Blaine Mtn in the Swan Range highlights that shorter pitches way down the runout can fail on the buried weak layer and carry major consequences when they release above a terrain trap. This lower slide likely piled debris 10'+ high on Jenny Lake.
Whumpfs and propagating test scores abounded as we stood gawking at these avalanches.
Photo: Josh Lipkowitz
