A series of natural avalanches that occur across a region over a relatively short time span.

Credit: Crested Butte Avalanche Center

An avalanche cycle occurs when many slopes avalanche naturally across a broad scale such as a drainage, region, or range.  Avalanche cycles can occur over the course of several hours or several days.  They are typically caused by a significant weather event spurring natural avalanche activity, such as heavy snowfall or rain, heavy wind loading, or rapid warming.  Avalanche cycles can be widespread across all terrain or occur on specific elevation bands or aspects.

A cycle of large wet avalanches caused by a significant and prolonged warmup. Similar activity occurred across the entire region. Credit: Flathead Avalanche Center

Avalanche cycles can vary in size and type of avalanche. This event produced a cycle of small to large soft slabs across the region. Credit: Crested Butte Avalanche Center

A natural cycle of very large deep slabs, caused by heavy snowfall and windloading on a deeply buried weak layer. Credit: Crested Butte Avalanche Center