雪崩，俗称白色雪龙，是在长年积雪的山中常有的自然灾害，是指大量的雪由斜坡表面上快速滑动下来，产生原因通常是覆雪处于一种「危险」的平衡状态下，如果稍微有外力作用，就会失去平衡，造成雪块滑动，进而引起更多的覆雪运动，使大量的积雪瞬间倾盆而下；附近的人及村庄往往不能幸免。

雪崩一般而言是由某一区域的积雪重量超过其强度所成（板状雪崩，slab avalanche），但也有时是是因为积雪渐渐的变宽所造成（松雪崩，loose snow avalanche）。雪崩在开始后，其速度会迅速的变快，也会带走路径上的雪，因此其重量及体积也会越来越大。若雪移动的够快，雪可能会混合一些空气，形成粉末状的雪崩，是一种密度流。

An avalanche (also called a snowslide or snowslip) is a rapid flow of snow down a sloping surface. Avalanches are typically triggered in a starting zone from a mechanical failure in the snowpack (slab avalanche) when the forces on the snow exceed its strength but sometimes only with gradually widening (loose snow avalanche). After initiation, avalanches usually accelerate rapidly and grow in mass and volume as they entrain more snow. If the avalanche moves fast enough some of the snow may mix with the air forming a powder snow avalanche, which is a type of gravity current.