A tourist in Jamaica was left on cloud nine after witnessing a rare and spectacular weather event at the end of October. Heading inside to take cover from an impending storm, Beckie Bone Dunning from Missouri looked to the skies and was greeted with a sight she had never seen before – a rainbow cloud.
After posting the picture to The Weather Channel’s Facebook page, she received a response from meteorologist Nick Wiltgen, who explained that the effect is produced by a phenomenon known as iridescence. This is caused when light is diffracted by water droplets and ice particles, causing the various wavelengths – each of which is detected by the human eye as a different color – to spread out.
Rainbow clouds often accompany thunderstorms, as the air above the clouds is forced upwards, causing it to expand and cool. As this occurs, moisture in the air condenses, forming a cap-shaped cloud. Colors can then appear around the edges of these clouds as the particles within them diffract the sunlight, giving a whole new meaning to the phrase "every cloud has a silver lining."