Summer and early fall here in central Florida are characterized by almost daily afternoon thunderstorms (usually about the time I get off work). They are caused by a combination of the high temperatures and high humidity this time of year. Sometimes they last only twenty to thirty minutes and other times they can last most of the afternoon and into the evening. Sometimes they present as just a wall of dark clouds coming towards us from the horizon, but often they are composed of some interesting and beautiful cloud formations. On this particular afternoon last week the clouds were especially pretty. The usual wall of dark clouds was overlayed with some fluffy, white cirrus clouds and then peppered with a number of smaller, very dark cloud fragments. The layers and the varying shades of grey-blue were quite stunning. I particularly loved the way the fluffy cirrus clouds had fingers that spread out over the darker clouds looking like streaks of paint in an artist’s work. In a way, I guess they are, with Mother Nature being the artist.

Cirrus clouds are formed by water from the humid air rising up into the higher, colder parts of the atmosphere. It condenses on fragments of dust up there and freezes. It’s these frozen ice crystals that form the beautiful light, fluffy, feathery cirrus clouds. The ice crystals in those clouds can also cause a number of visual artifacts including halos and arcs. And just as an aside, it’s also frozen ice crystals forming on exhaust particles that create the contrails we see behind high flying jet planes. There are an amazing number of cloud types and many of them are quite attractive, but I must say I have always liked the feathery look of the cirrus clouds, and against the background of the dark storm clouds they are particularly pretty.