Clumps of snow falling from tree limbs. A potential sign of unstable snow.

Credit: Post Register

Clumps of snow falling from tree limbs is a common sign of rapid warming that can be associated with unstable snow. Tree bombs indicate changing conditions as fresh or cold, dry snow becomes wet from warming. Tree bombs are common precursors to avalanche activity on adjacent slopes, and they can also act as triggers for avalanches by cratering into and destabilizing the snow surface.

A tree bomb that pinwheeled downslope.  Credit: Gallatin National Forest Avalanche Center