26 January 2015

Word for the day: virga

Our local weatherman used the term "virga" several evenings ago when he pointed out that snow seen on the radar was not reaching the ground:
In meteorology, virga is an observable streak or shaft of precipitation that falls from a cloud but evaporates or sublimes before reaching the ground. At high altitudes the precipitation falls mainly as ice crystals before melting and finally evaporating; this is often due to compressional heating, because the air pressure increases closer to the ground. It is very common in the desert and in temperate climates. In North America, it is commonly seen in the Western United States and the Canadian Prairies. It is also very common in the Middle East, Australia and North Africa.

The word virga is derived from Latin meaning "twig" or "branch".
I've seen this phenomenon all my life (especially when monitoring clouds while hiking or fishing) but didn't know the term.  And now I also realize that for decades I've been incorrectly using "sublimate" as a verb ("A lot of the snow sublimated this weekend") when I should have said "sublimed."  You learn something every day.  

1 comment:

  1. When I saw that you said sublimate was the wrong word I immediately went to my big pile of dictionaries thinking this shall not stand! Since I too had been using sublimate as you said for my whole life. And so now I guess I'll have to reform my ways. Humph.
    But I think you could still get away with saying, " Hey, look how that warm air is sublimating that rain as it falls." And then slink away not utterly devoid of dignity.


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