Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Likely
- Tamaño
- 3
The Dry January Layer (DJL), formed during our January dry spell, can be found on upper- and mid-elevation W‑N‑E facing slopes, and even on lower-elevation NW‑N‑NE terrain. This layer is responsible for much of the avalanche activity observed over the past few days.
Large slabs now exist across much of the range, resting on the very weak DJL. This strong-over-weak structure has, and will continue to, produce large, destructive avalanches. These slabs can propagate widely and may be triggered remotely from a distance.
If you’re considering “safe” travel on a ridgeline, remember that you could become a hazard to those below if you trigger, or remotely trigger, a slide on adjacent slopes, especially in busy terrain. Always be aware of who and what is above and below you. Safer riding conditions are found on slopes less than 30° with no overhead hazard.
As we move further from the initial loading event, obvious signs of instability may not be as apparent, such as cracking or collapsing, but the poor snow structure still exists. The only way to know if the weak grains remain is to stick your shovel in the snow. Even as the likelihood slowly decreases, the consequences of these types of avalanches remain extremely high. The risk is not worth the reward.
Michael Davis had an excellent observation from Monte Cristo, where he found about 35" of new snow sitting atop weak faceted grains and got propagation on his 22nd tap.
