An avalanche caused by snow losing its strength after becoming damp, moist or saturated with water.

Most avalanche professionals make a hard distinction between dry snow and wet snow avalanches because they are such different beasts. They are caused by different processes, they fail and fracture differently, they are triggered differently and they move differently down the slope. Really, there is a continuum between wet and dry avalanches and professional workers use the words: dry, damp, moist, wet and saturated to describe the continuum. Wet avalanches cause relatively few avalanche fatalities, consequently, they are studied less and are not as well understood.

Dry AvalanchesWet Avalanches
What causes them?Caused by putting too much additional stress on the snowpackCaused by decreasing the strength of the snowpack
How do they involve people?Triggered by the victims or someone in the victim’s party in 90 percent of casesDifficult for people to trigger. Most accidents are from natural avalanches
What are the contributing weather factors?Usually loading of wind drifted snow or loading of new snowUsually by rain, prolonged melting by sun or very warm temperatures
How do they flow?Fast (80 mph or so) usually with a dust cloudSlower (10-40 mph) like concrete and usually without a dust cloud