Like giant breakwaters in the ocean surf, magnificent cloudbursts crashed over Smith Mountain Lake in Virginia on Tuesday night.
These rare clouds, known as Kelvin-Helmholtz instability waves, were spotted and photographed around 8:30 pm by Amy Christie Hunter.
"It was the coolest cloud formation I've ever seen!" she wrote on her Facebook page. "It was so amazing."
Hunter's photo has become viral and appears on local and national television programs and websites.
Kelvin-Helmholtz instability clouds are formed from the variation in air density between adjacent layers and the resulting difference in wind speeds known as shear. These clouds are extremely short-lived and break in the same way as a wave on a shore – because the lower layer moves slower than the upper layer and the upper builds up and crashes.
To trigger these wave clouds, you need a disturbance or disturbance to disturb the airflow. Usually they only last about 10 minutes before collapsing.
They are most abundant near mountain ranges due to the overlying layer of air, but can form everywhere and demonstrate the flowing nature of the atmosphere.
Here are two more textbook examples for these cloud formations from 2015:
From Breckenridge, Colorado.
From the Galapagos Islands:
More about Kelvin-Helmholtz wave clouds
Radical Kelvin Helmholtz wave clouds in the Rocky Mountains
image of the week: Remarkable wave clouds paint the sky over Utah
Image of the week: Surfing for snow lovers, incomparable Kelvin Helmholtz clouds in Breckenridge
Shark fins in the sky: Awes Some Kelvin-Helmholtz clouds from the Galapagos Islands