Dogwoods, willow and alder indicate regular seasonal avalanche activity. Young aspens indicate intervals of 5-15 years. Large, dense evergreens indicate a return interval of 50 years or more. Unusual snow conditions produce unusual avalanches. Look at the snow around the base of trees for other clues.
Most avalanches happen during or shortly after storms.
If the snow in the trees hasn't settled, the snow on the ground may not have had enough time to stabilize, either. The direction a slope faces affects its susceptibility to avalanching because of the influence of weather . Shady, northerly aspects take longer to stabilize after a storm and favor the growth of weak faceted crystals . In the Northern Hemisphere, these slopes are often recently glacier-carved and steeper than similar slopes of other aspects. Deeper snow on these shady, protected aspects tends to cover anchors, but trees will often be denser, as well.