Avalanches depend on a balance of stress vs. strength in the snowpack. When stress exceeds strength we get avalanches; therefore, to get an avalanche either increase the stress or decrease the strength. Dry snow avalanches occur when stress increases with the additional weight of new snow or wind-blown snow. Wet snow avalanches occur when the strength decreases with the addition of liquid water from warm air temperatures, sunshine, or rain.
Advisory Year