"Fire rainbows” were recently spotted above the Isle of Palms in South Carolina. Although to burst your colorful bubble, the clouds don't contain fire nor are they technically a rainbow. Boo.
These weather anomalies are called circumhorizontal arcs. They occur when the Sun has risen higher than 58° in the sky and there are wispy cirrus clouds present. Since the altitudes at which these clouds reside are so cold, they are formed of ice crystals. This allows the sun’s rays to refract through them, creating prisms and therefore a pretty rainbow.
Image Credit: Flickr (CC BY-SA 2.0) / Attila Magyar
How often we see these rainbow arcs depends on latitude and weather conditions – most often, they occur at mid-latitudes, which explains why they’re reasonably common in the U.S. In fact, the potential to see these arcs is around five times greater in Los Angeles than in London. But hey, we never get any form of nice weather anyway.
Fire rainbow seen over South Carolina. Image credit: Instagram user Carole Rich Williams
[H/T: Discovery News]