Wednesday, June 29, 2011

Jellyfish clouds and Virga

(ABOVE: Connie Clark took these pictures near sunrise in Muskogee. These small jellyfish-looking clouds are producing "virga.")

KJRH viewers emailed us unusual looking cloud pictures on the morning of June 27. "What is this? What type of clouds are these?" were common questions.

The answer: "virga".

Virga is rain which evaporates before reaching the surface. The small cumulus clouds pictured above and below were producing light rain, but the rain wasn't heavy enough to reach the ground.

Virga occurs when rain falls through a layer of dry air between the cloud and ground. If the rain keeps falling, then the dry layer moistens. The evaporation cools the air allowing the air to better support the rain. The rain eventually reaches the ground.

No rain was reported in Tulsa, but light rain was observed east of Tulsa in the less dry air.

As far as the appearance, I call these clouds "jellyfish clouds".The overly wispy-looking tails and unusual coloring was from the evaporation plus time of day. Connie took this pics at 6am. The hours near sunrise and sunset are often the most beautiful for photographing weather.

(BELOW: Jellyfish clouds! Looks spooky as the rain evaporates just before sunrise. Thanks for the pics, Connie. )

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