Tap the blade and observe the snow for failures. This is much like a giant compression test that give good information about the stability of a suspect slope. Isolate a block of snow on a representative slope in a safe location, 1.5 metres upslope, and 2 metres across. The slope angle should be at least 25 degrees steep on undisturbed snow with no natural anchors and an even snow pack. The back of the column can be cut with a ski, pole, large snow saw, or cord.
Stability is rated by how much force it takes for a layer of snow to fail.
The block slides during digging or cutting 2 The skier approaches the block from above and gently steps down onto the upper part of the block 3 Without lifting the heels, the skier drops from straight leg to bent knee position, pushing downwards and compacting the surface layers. The skier jumps up and lands in the same compacted spot. The skier jumps again on to the same compacted spot. For hard or deep slabs, remove skis and jump on the same spot. For soft slabs or thin slabs where jumping without skis might penetrate through the slab, keep the skis on, step down another 35 cm., almost to mid-block and push once then jump three times.