Stable vs. Unstable Snowpacks
Having a slab on a weak layer that’s on top of a good sliding surface constitutes an unstable snowpack,
the kind most prone to avalanching. An unstable snowpack contains both weak and strong snow layers. A weak layer consists
of poorly bonded or unconsolidated snow, while a strong snow layer has well consolidated snow, such as
a slab.
A stable snowpack is generally more homogeneous and lacks significant density differences throughout the pack. It can contain:
- Snow that’s all strong
- Snow that’s all weak
- A layer of weak snow on top of a layer of strong snow
Over time, the bonds between weak layers and slabs may strengthen, stabilizing the pack. A stable snowpack is not prone to avalanching.