Cloud Genus

Above: Cloud Genus

Cloud Genus

Cloud formations are difficult to classify, identify, and predict due to the many variables necessary to form a single cloud formation. However, there is a need to differentiate these weather formations so that science can begin to understand our planet's weather.

Low-level clouds are classified by their height at sea level, usually between 0 to 2 kilometers. These are the closest clouds to the Earth’s surface, and often, the most visible.

The Cloud Genus Stratus

The cloud genus stratus is described to be layered, flat, and horizontal in nature. Its height from sea level ranges from 0 to 2 kilometers. The identification of stratus is clearer when it is at a height; its unique characteristic being a level pancake base. But stratus clouds also occur at lower heights though its form does not make it easy to identify. The other way of distinguishing stratus clouds closer to the ground is through precipitation, which is usually in the form of a light fog or drizzle.

Due to the natural varying shapes of the cloud genus stratus, here are the different types under it:

  • Stratus Undulatus. The unique identifier of the stratus cloud, which is a flat level base, transforms into a foundation in the form of wavy lines in the stratus undulatus.


  • Stratus translucidus. Like the stratus undulatus, the waves at the base are characteristic to the stratus translucidus. However, the cloud formation is thinner, and the shapes of the sun or moon can still be seen.


  • Stratus Opacus. This form of the cloud genus stratus is heavier and thicker, completely hiding the sun or moon.


  • Stratus praepecipitatio. More commonly experienced as a fog or light drizzle in the mornings, the precipitation can take the form of very light snow or rain.


  • Stratus Nebulosus. Described as a gray mass, without the visible level base. The levels of the cloud may be slightly present.


  • Stratus Fractus. The layers of the stratus fractus are distinct from each other, with each layer often catching a different hue. The stratus fractus is not stable, and usually shifts form quickly.

The Stratocumulus Clouds

The stratocumulus cloud is the halfway cloud between the cumulus cloud and the stratus cloud. The base of the cloud is often wavy, as it is with stratus clouds, although the main body of the cloud is in clumps, the common characteristic of the cumulus cloud. The stratocumulus cloud frequently occurs in number, being relatively small and distinct from each other, herding in bunches in a random manner.

Turbulence is often the cause of this cloud formation. Air layer instability forms convections and invections of the air currents, creating the stratocumulus effect. In terms of weather conditions, the stratocumulus clouds are associated with light rain, although if the blue sky can be seen along with the stratocumulus clouds, the condition is only temporary.

Under the stratocumulus clouds are three major species:

  • Stratocumulus castellanus. This cloud formation is the shape of a towering balloon-like structure of clouds.


  • Stratocumulus stratiformis. The shape of the stratocumulus stratiformis is similar to that of loose drapes. The bulge is underneath the cloud.


  • Stratocumulus lenticularis. The stratocumulus lenticularies is a shapeless mass of clouds with a flat base.

The Cloud Genus Cumulus

Cumulus clouds are the cotton ball clouds with a flat base, and they are often seen as a huge mass of bulges. The cumulus effect comes from a certain condition of air convection and turbulence, and as long as the conditions are maintained, the cloud formation increases in mass. The formation of the cumulus cloud begins at a very low height; sometimes beginning at 300 feet, and gradually increases in size and structure.

The cloud genus of cumulus clouds appears as a sign of a really good weather, but interestingly enough, it can also indicate a really bad weather. If the cumulus cloud appears in good weather, it is an assurance that the weather will stay clear of rain for at least 30 to 45 minutes. However, should the cumulus cloud begin to precipitate, there is a strong probability that it will turn into a cumulunimbus cloud, and in this case, will bring thunderstorms and inclement weather.

  • Cumulus humilis. Known as a sign for good weather conditions, this type of cumulus cloud appears with patches of blue sky between them. They are signs of good weather for as long as several hours, but can also precede stratocumulus cloud formations.


  • Cumulus fractus. Cumulus fractus is an accessory cloud, usually a piece of a cumulus cloud broken off from the body, although it sometimes forms on its own.


  • Cumulus mediocris. A cumulus cloud midway into developing into a full cumulus cloud.


  • Cumulus congestus. This is a cloud that forms when cumulus mediocris starts to turn into a full cumulus cloud.

Cumulonimbus Clouds

Cumulonimbus clouds are referred to as bad weather clouds. These cloud types are immense cloud formations that bring heavy rain. These towering structures can appear alone or in groups, and lightning usually accompanies a cumulonimbus cloud group in the center of the structure. This type of cloud is often the result of a cumulus congestus cloud formation, and can further develop into a thunderstorm or a special type of weather condition known as single cells, multicells, or supercells.

A cumulonimbus cloud can begin at low level and reach up to the mid level height of clouds, which is around two to four kilometers above sea level. The foundation of a cumulonimbus cloud covers a huge area, and can reach up to several miles across. Mature cumulonimbus clouds can be identified from afar by a recognizable anvil-like appearance, caused by wind and air currents, as well as temperature changes.

Two species of clouds form the cumulonimbus cloud, and these are:

  • Cumulonimbus calvus. A generally smooth formation of clouds, losing its sharpness and shape only at the top of the cloud formation.


  • Cumulonimbus capillatus. The upper part of this cloud formation appears sharper but it is generally streaking or frayed.

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