Photographer captures rare 'fire rainbow cloud' above Florida. Another spectacular light show. Ken Rotberg spotted unusual phenomenon as sun dropped behind a storm cloud in the early evening Rare sight also known as a 'circumhorizon arc'
Fire rainbows are the rarest of all naturally occurring atmospheric phenomena. For a fire rainbow to occur, cirrus clouds must be feet in the air with the precise amount of ice crystals, and the sun must hit the clouds at 58 degrees. (a/k/a Sun Doggies)
This "fire rainbow," or iridescent cloud, was captured over South Florida. They are technically known as iridescent clouds, a relatively rare phenomenon caused by clouds of water droplets of nearly uniform size.