Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Very Likely
- Tamaño
- 1.5–3
Multiple weak layers are buried in the upper 1-2 feet of the snowpack. These layers produced human-triggered and natural avalanches prior to the intense storm that is taking aim at our region today. Up to one foot of dense snow (1" of snow water equivalent) has already fallen at upper elevations, and an additional 10-20 inches of snow (0.75-1.5 inches of snow water equivalent) will arrive by tomorrow morning. Our weak upper snowpack will not be able to handle this rapid load.
Avalanches will be very easy to trigger today, and many will fail naturally. Thanks to the layers of weak snow, these slides will break widely and will be able to wrap around terrain features and involve multiple starting zones. This produces very large, unpredictable avalanches with deep piles of debris. Importantly, you will be able to trigger these slides remotely — from a distance away from the slope that avalanches. This means that you can trigger slides that fail on steep slopes above you, and run down into flat terrain below. Avoiding this problem includes avoiding terrain threatened from above.
(2/19/2026)
Buried surface hoar under 10 inches of recent snow.