Freezing rain

Freezing rain begins as snow falling from a cloud towards earth. It melts completely on its way down in a layer of warm (above freezing) air and then supercools in a small layer of cold air just before it impacts the surface. Due to it being supercooled the water freezes again upon impact.

If the ground temperature is below freezing temperature, freezing rain can give rise to ice storms, in which ice accumulates to thicknesses of several inches wherever the freezing rain is falling. Trees, electricity pylons and other objects can be severely damaged by the enormous weight of ice that results. One particularly severe ice storm struck eastern Canada in 1998.

See also: hail, sleet, ice storm