In situations where the weak layer is near the top of the snowpack, the collapse of a weak layer will result in cracking on the surface of the snow, as well as “wumph” sounds where air from the weak layer is pushed out as the snow settles above it. Weak layers may also lead to naturally triggered avalanches in the area you are skiing. Be alert to recent avalanche activity in the area you are skiing and use that information to asses the stability of the likelihood of weak layers in the snowpack you are considering skiing. But just because these signs may not be present, that doesn’t mean that the weak layer isn’t present deeper in the snowpack.

Weak layers will always have a breaking point in terms of the load they can support. “Load” refers to the force that a skier places on the snow below their feet. The minimum amount of load is generated by a single skier walking, or skiing carefully down the mountain. By jumping off of cliffs or features, falling, or adding additional skiers on a single face, the load is increased. Therefore it is important to make decisions about how and where you tour and ski based on how much load you believe the snowpack can withstand.

The thicker the weak layer is the stronger it is. From research done in Switzerland, 65% of all the avalanches had a weak layer of less than 2 cm. The depth of the weak layer is a key factor in its strength. The deeper the weak layer is, the heavier load it can support. At a depth of 80cm below the surface, the load from a skier is only ¼ of the load at 20cm.

Loose snow with low hardness will cause a skier to sink deeper down into the snow. If the snowpack has a weak layer, the skier will come closer to this layer, placing more load on it and increasing the probability of triggering an avalanche. In loose snow the forces from a skier goes pretty much straight down. Harder snow causes the pressure on the snow to spread out, resulting in less load on the weak layer, decreasing the chance of an avalanche.