Snow Slope Slope Angle Avalanches can occur on slopes ranging from 10-60 degrees, but are most common between 30 to 45 degrees. As a rule of thumb, if it is steep enough for good skiing, it can avalanche. With all other factors being equal, the shape of the slope can increase the probability of an avalanche.
Convex slopes are less supported and more likely to avalanche, especially near the top of the slope.
Concave slopes are better supported making them generally more stable. The nature of the surface of the slope can have a great effect on the stability of the area. Smooth slabs and grassy meadows are good sliding layers for an avalanche. Boulder fields, shrubs, and small trees can be good anchors for the snow until they become buried, but must be assessed cautiously. Shrubs can bend over time due to snow creep and become much less effective later in the season.