Virga

A virga, also called a dry storm, is an observable streak or shaft of precipitation that evaporates or sublimates before reaching the ground.

In some instances these pockets of colder air can descend rapidly, creating a wet or dry microburst which can be extremely hazardous to aviation.

Conversely, precipitation evaporating at high altitude can compressionally heat as it falls, and result in a gusty downburst which may substantially and rapidly warm the surface temperature.

[citation needed] The word is derived from the Latin virga, meaning rod, sprig, staff, branch, shoot, twig, spray, sprout, switch or graft.

[citation needed] In September 2008, NASA's Phoenix lander discovered a snow variety of virga falling from Martian clouds.