Couple of weeks ago a rare sight showed up in our afternoon sky. Many viewers sent in interesting pictures of rainbows in the clouds when it wasn't raining. So today we'll show you what causes these fire rainbows.
Mother Nature gave us a rare weather treat with rainbows in the clouds even though we didn't get a drop of rain.
Conditions have to be just right for these fire rainbows to form. The clouds must be wispy high clouds called cirrus at around 20,000 to 30,000 feet. There must be a good amount of ice crystals and the sun angle has to be just right.
Sunlight is made of all the colors of the spectrum. You see it as white because you are seeing all the colors combined. The ice crystals act like a prism to bend the light and make different colors. The crystals in the cirrus clouds are shaped like thick plates with their faces parallel to the ground. The light enters through the vertical side and refracts the light so the whole cloud lights up as a rainbow.
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