What the Cloud is it?

When I was a kid there were three basic types of clouds with all clouds falling into a combination of those three:

Cirrus, stratus, and cumulus. Throw in a Alto and a Nimbus, plus a combination of the three clouds together, and you got all the clouds you ever thought you needed. It is all shown in a handy, dandy power point from Professor Nenes who teaches at the School of Chemical & Biomolecular Engineering at Georgia Institute of Technology. Simple, basic cloud fun… but NOOOOOOO!

Today, according to Twisted Sifter you have the basic clouds, plus fifteen more (count them – you have to use your fingers and toes for this one!)

I have to admit, they are pretty spectacular, which is why I’m using them in this post. I’ll just be posting the bits and pieces I like on this page. For the complete description you’ll need to click on the link to the Twisted Sifter web page above. I must note that, like me, Wikipedia is a favored information source – you go!

  1. Lenticular clouds, (Photograph by Coconino National Forest) obviously named for their lens-shaped. Although they can be separated into three of our basic clouds as outlined by Professer Nenes, They have much cooler names. They’ve also been accused of being the cause of Unidentified Flying Object (UFO) sightings.

  1. 2.      Undulatus asperatus clouds, (Photograph by brainiak005 on Reddit) which translates more or less as roughened or agitated waves, really? Couldn’t they be called undulates because they seem to undulate across the sky?

  1. 3.      Night clouds or noctilucent clouds, (Photograph by Martin Koitmae) made of crystals of ice and form under very restrictive conditions. What’s super cool – heh, heh, I made a pun… – is that they are a recent discovery and no one really understands how they’re formed, only that you can only see them 50-70 degrees from the equator (north and south), and when the sunlight hits them from below the horizon. How cool is that?

  1. 4.      A fallstreak hole, (Photograph by H. Raab) is a large circular gap that can appear in cirrocumulus or altocumulus clouds, believed to be a jet passing through disrupting in the stability of the cloud layer inducing the domino process of evaporation which creates the hole. They too are often mistaken for or attributed to unidentified flying objects. Who knows, maybe someone out there knows something…

  1. 5.      Mammatocumulus clouds, or mammatus,  – mentioned on a previous post – (Photograph by Matt Saal) are pouches hanging beneath the base of a several types of clouds including cumulonimbus, altocumulus, altostratus, stratocumulus, and cirrus. They are mostly associated with anvil clouds and can also be found under clouds formed by volcanic ash. If anyone knows anything about Latin, you can figure out where they got the name mammatus from.

  1. 6.      A wave cloud, (Photograph by NASA Satellite Image) they form at the cooled crests of waves as air flows over raised land ranges such as mountains. As air travels through the wave, it lifts and descends and if there’s enough moisture in the atmosphere clouds will form at the cooled crests of these waves, as the wave descends warm air evaporate part of the clouds. The base on the leeward side is higher than on the windward side, creating the wave pattern.

  1. 7.      Cloud iridescence, (Photograph by Esther Havens (Light the World)) is a fairly uncommon phenomenon, most often observed in altocumulus, cirrocumulus and lenticular clouds, and very rarely in Cirrus clouds caused by small water droplets or small ice crystals of similar size, their cumulative effect takes on the structured form of a corona, a central bright disk around the sun or moon surrounded by one or more colored rings. This, I think, is the coolest of all the clouds put together!

  1. 8.      A Roll cloud, (Photograph by Capt. Andreas M. van der Wurff ) a low, horizontal, tube-shaped, and relatively rare type of arcus cloud (a low, horizontal cloud formation). A solitary wave called a soliton has a single crest and moves without changing speed or shape which appears to be “rolling” about a horizontal axis. Probably the easiest explanation so far…

  1. 9.      A shelf cloud, (Photograph by John Kerstholt) is a low, horizontal, wedge-shaped arcus cloud attached to the base of the parent cloud, usually a thunderstorm. The leading (outer) part of the shelf cloud raises up, while the underside appears turbulent. Cool air sinks and out across the land surface cutting under warm air being drawn into the storm’s updraft. The lower air cools and lifts the warm moist air; water condenses, creating a cloud which rolls with the different winds.

  1. 10.  A pyrocumulus, or fire cloud, (Photograph by Gayle Jones) is a dense cumuliform cloud associated with fire or volcanic activity produced by the intense heating of the air from the surface causing the air to rise. Volcanic eruptions, forest fires, and occasionally industrial activities can induce formation of this cloud. The detonation of a nuclear weapon in the atmosphere will also produce a pyrocumulus in the form of a mushroom cloud which is made by the same mechanism.

  1. 11.  A Foehn gap, or wave window, (Photograph by Dhaluza) if there is sufficient and cool air in the atmosphere form specific cloud formations called lee waves, or standing waves and the rotor; though the site doesn’t explain what the rotor is. These clouds do not move downwind as clouds usually do, but remain fixed in position relative to the obstruction that forms them. Compressed air in the center of each wave evaporates the cumulus or stratus clouds creating a window.

  1. 12.  An actinoform or actiniform cloud, (Photograph by NASA) Okay, these are the second coolest cloud, in my opinion… a collection of low clouds form a radial structure. They can spread 190 miles (I’m American, I use American measurements) across so are normally only seen in a satellite image. They are shallow, and would be classified as stratocumulus clouds by an observer on the ground.

  1. 13.  Polar stratospheric clouds, (Photograph by Alan Light) also known as nacreous clouds, are implicated in the formation of ozone holes; because they catalyze ozone destruction, and increase ozone destruction. The dry stratosphere rarely allows clouds to form. However, in the extreme cold of the polar winter clouds of different types may form and are classified according to their physical state and chemical composition.

  1. 14.  A pileus, also called scarf cloud or cap cloud, (Photograph by NASA) is a small, horizontal, altostratus cloud appearing above a cumulus or cumulonimbus cloud. Formed by strong updrafts in the moist air at lower altitudes, they cause the air to cool giving the parent cloud a “hoodie.” They can also form above some mushroom clouds of high-yield nuclear detonations; in that context they are called ice caps.


And finally!!!

  1. 15.  The Morning Glory cloud, (Photograph by Mick Petroff) are Roll clouds that can be up to 620 miles long, 1 to 2 0.62 to 1.2 miles high, 330 to 660 feet above the ground and can move at speeds up to 37 miles per hour. Sometimes there is only one cloud, sometimes there are up to eight consecutive clouds.


I hope you enjoyed this information as much as I did. Who knew, besides meteorologists, that clouds could be more than fluffy cotton balls creating patterns across the open field of blue? Their majesty rules the ceiling of our world and the inner reaches of our imagination. I love clouds from the light fluffy cotton balls to the black angry storm clouds. They not only incite the imagination, but inform or forewarn us of the day, or night, ahead.

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