1. Search for instability
Looking for evidence of recent avalanches is a good starting point. Observe the whole landscape for any debris that could have been moved by a snow slide. Signs of activity means the rest of the snow could be unstable.
2. Check for cracking
If the snow is cracking, it’s a sign of unstable slabs in the area. An unusual number of cracks underfoot or cracks that suddenly appear are a good indication of moving snow, and possible avalanches.
3. Spot significant snowfall
If a large volume of snow has fallen in the last 24 hours, it won’t have had time to compact together in a stable layer. Introducing rain or wind to a large amount of fresh snow is a recipe for an avalanche.
4. Listen for thuds
Sounds from below the ground can be caused by snow collapsing in deeper layers. This is a warning sign that there are weak snow layers below that could trigger a slide. Often the ground can feel hollow underfoot.
5. Monitor temperatures
If the air has been getting warmer, rising above 0° C, it can cause partial melting within the snow layers. Melting makes snow heavier, and as it becomes wetter it gets slipperier. This can cause wet avalanches.
6. Understand the terrain
Terrain can reveal a lot about the potential for an avalanche. Avalanches are most likely to occur on slopes between 30 and 45 degrees. In winter, slopes on the south side of a mountain are more stable than the north-facing ones.