Posts Tagged ‘Cloud types’

Just for fun!

The Latin students among you will readily recognize what sort of ideas are expressed by all these syllables, which are very clear and definite.

Stratocumulus perlucidus below Cirrus intortus

Upper level cirrus in various tangles with a large sheet of cumulus that still allows the light to come around and through.

Stratocumulus means a sheet of lumpy clouds. Stratus is sheet; cumulus is lumpy or humpy. Perlucidus means the light goes around it — the sheet does not cover the sky. In fact, convection in the center of the sheet makes it high there while the edges are not growing.

Above the cumulus — in the upper section of the photo, but also thousands of feet higher in the sky, the cirrus, the wispy clouds, are tangled in various ways. Having words for it makes it easier to remember what you saw and how it was laid out. Figuring what weather is implied is a different exercise, but The Weather Identification Handbook gives some basic clues.

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Just a quick note here, but I have been skimming The Cloudspotter’s Guide by Gavin Pretor-Pinney, and am about to nominate this as the book I most wish I’d used for my course. It’s written with a happy mix of science, observation, and reflection. Unfortunately, the photos are black and white, but you can always look up to get your fill of color.

And, yes, there really is a Cloud Appreciation Society, and of course they maintain a website, which has, without any competition, the most extraordinary cloud photos I have ever seen.

Did you know that there is a small town in Australia which is home to a unique cloud formation called the Morning Glory? It is a kind of cloud roll which forms in the spring and which is the very Mecca of gliders because you can ride its wave as surfers ride the waves of the sea. Take a look!

There is also a wonderful gallery of photos of all the principal cloud types, and as these are sent in by members from all over the world, they are breathtaking in unexpected ways. Various kinds of displays within clouds are also illustrated with extraordinarily beautiful hotos. Here’s a photo of some fallstreaks, cloud holes that are caused by the passing of an airplane whose exhaust has seeded a portion of the cloud and caused its droplets to fall out.

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Cumulus Fractus

Clouds this afternoon are cumulus fractus – the kind of cumulus you get at the end of a storm — ragged-edged, wispy, and scooped out, though still mostly bright and white. They are low, probably no more than a mile high, separated by large amounts of clear blue sky. They don’t look like cauliflower or sheep or popcorn, nor do they have the flat bases of new cumulus, so the average form could be turned upside-down without looking strange. Indeed, these are the types of clouds that look like bears and dragons and roosters – I definitely saw a rooster today — and all sorts of things. Once they were puffy cumulus, but now they are breaking up and evaporating.

Even so, they are much bigger than they seem. Stretch out your thumb and see how well it covers a large house from the distance of half a mile. Or, if your location doesn’t let you see houses that far away, try choosing a water tower and a place in town where you can view it from something between a half -mile and a mile away. Stretch out your arm and see how well your thumb covers the water dome. Compare that with how much of the nearest overhead cloud you can cover in the same way. Clouds on the horizon are just as large, of course. This exercise will help you to rightly perceive the sizes of cumulus fractus clouds any time you see them.

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