This type of avalanche often begins at a point and spreads out as it goes. Ice fall avalanches occur when a glacier encounters a steep drop. Ice fall avalanches are unrelated to temperature, time of day or any other factors, despite conventional wisdom to the contrary. The best way to avoid these avalanches is to not travel beneath ice cliffs and through ice falls, or if necessary, roll the dice and travel through quickly. Roof avalanches can be deadly for the unwary and will often release as the inside of the house or cabin warms up.
Cornice fall avalanches occur when cornices break loose from the lee side of ridges.
Cornices look like frozen ocean waves stretched along mountain ridges. The snow that forms cornices is very dense and hard, yet can be extremely fragile. It is often difficult to determine from the ridge top where the ground ends and the overhanging cornice is not supported. This type of avalanche is easily avoided by staying back from the peak of ridges, but can be deadly as the victim tumbles downhill amid massive, hard and heavy chunks of snow which often trigger secondary slab avalanches as they pass. The most dangerous type of avalanche is the slab avalanche .