Mississippi State University Weather

What’s that term, Virga?

Have you ever read or hear the term “Virga”? Maybe you have looked at radar seeing shades of light green, but there is no rain? “Virga” meaning “branch” or “twig” in Latin is precipitation falling from clouds and evaporating before it hits the surface. Cool right? Virga often looks like streaks in the sky or shafts under a cloud base. Virga can happen when low humidity and high temperatures make precipitation evaporate before it hits the surface.

Photo 1

This process mainly takes place in Canada, the Middle East, Australia, at high altitudes, and in desert areas around the globe. You can also catch a glimpse of virga in western parts of the United States where clouds produce lightning, thunder, and no measurable rainfall at the surface. In the winter, virga can happen when rain or light snow is spotted in the sky and the surface is drier than aloft. It can also happen before a microburst thunderstorm.  Virga is pretty rare in the southeast so if you happen to catch a glimpse of the awesome streaks in the sky – make sure to take a photo. ~Meagan Massey

Photo 2

 

 

 

Photo 1 Citation:

Jensen, Susan. Virga in Washington. 2015. EarthSky. Web. <http://earthsky.org/earth/virga-is-rain-that-doesnt-reach-the-ground>.

Photo 2 Citation:

Ratliff, Ron. Virga in Utah. 2015. Mexican Hat. EarthSky. Web. <http://earthsky.org/earth/virga-is-rain-that-doesnt-reach-the-ground>.