Persistent Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Possible
- Tamaño
- 2–3
The old, weak snow continues to slowly adjust to the dense slab of more recent snow above it. This adjustment takes time and does not happen at the same rate in all locations. No new avalanches have been reported since Monday, and many tests/observations show a strengthening trend in the snowpack. However, some snowpit tests targeting the persistent weak layer produced unstable results each of the last two days. Overall, it has become more difficult to trigger a persistent slab avalanche. Still, it may remain possible in some places, especially in areas where the weak layer may be particularly weak or where it may be closer to the surface. If one of these avalanches does occur, it would be very large and have dire consequences.
Many people will not see any evidence of the persistent slab problem today, and the snowpack may not provide obvious clues like cracks or whumpfing. Unfortunately, a large, unexpected avalanche on a seemingly stable slope might be the first and only clue that the slope remains unstable. An avalanche could still occur on a slope that already has several tracks on it. Even though the number of avalanches has decreased, the consequences have not.
The most reliable way to reduce the potential consequences of an unexpected, persistent slab avalanche is to step back from the terrain where the problem might exist. You can do this by choosing SE-S-SW aspects where this avalanche problem does not exist or sub-30-degree terrain with no other steeper connected terrain above or to the side. If you choose to go into areas where this problem could linger, reduce your exposure as much as possible. Travel one at a time, limit time in avalanche terrain, and regroup in safe zones away from potential run-out areas.