Clouds of the kind called cirrus, which is the Latin word for ‘curl’, float higher than those of any other kind, their average height above sea-level being about 10,000 meters (33,000 feet) – quite more than that of the world’s highest mountain. They are made up of tiny particles of ice, and are always white. They resemble, feathers or ribbons, spreading out like the ribs of a fan, and are sometimes called mare’s tails. Cirrus clouds are usually regarded as a sign of coming wind.
Additionally, the height at which clouds float depends on the type. Clouds are usually categorized into three types:
- High-Level Clouds
- Mid-level Clouds
- Low-Level Clouds
In addition to Cirrus, there are several other types of high-level clouds. Cirrocumulus is one such type. These clouds are considered as one of the most beautiful in the sky. They can be recognized by their small patterns of white fluff that spread for miles in addition to forming around 5 km above the surface. Often referred to as ‘mackerel skies,’ these clouds can sometimes develop greyish color, which makes them look like scales of fish.
Cirrostratus clouds possess an appearance similar to a sheet and sometimes look as if the sky is being covered by a curly blanket. Both the sun and moon can peer through them as they are quite translucent. The color of these clouds ranges from light gray to white. Lastly, Cirrostratus clouds always travel in the western direction, and as they are spotted, it usually means that there are high chances of rainfall in the next 24 hours.
Altocumulus are normally found near to the surface and contain water droplets, which also helps with their formation. As they move higher up, they may also hold onto ice crystals. If Altocumulus clouds appear with some other cloud type, it means that a storm will follow. However, one cannot expect heavy rainfalls from the clouds as they produce light to moderate showers.
Altostratus clouds will spread thousands of square miles and produce snow or light rain. Even though these clouds are not capable of producing heavy rain, but sometimes they can deliver a pounding by joining with other cloud types such as nimbostratus clouds. Altostratus clouds are often called ‘boring clouds’ as most of them are featureless and are only smooth and gray by appearance.
Nimbostratus clouds are dark and thick, fully capable of blocking out the sun. These clouds are bearers of heavy rain, and even though they are mid-level clouds, they can sometimes descend to a lower altitude. The name Nimbostratus is a Latin word, which means, spread out the rain.
Stratus clouds are thin and cover a large area of the sky. As they descend towards the ground, they usually take the appearance of fog or mist. The long horizontal layers are a defining characteristic of this cloud, which gives it a fog-like appearance. Due to their benign nature, stratus clouds produce light snow or showers if the temperatures happen to fall below the freezing point. These clouds are most common in mountainous and coastal regions.
Cumulonimbus clouds are also called tower clouds due to their vertical development, and in appearance look similar to fluffy cumulus clouds. However, the formation of these clouds is much larger. The sight of cumulonimbus clouds usually means that there is a thunderstorm taking place somewhere. These clouds have an irregular rain pattern i.e. it will pour and pause for a few moments throughout the day. While they are near to the surface, they are mostly made of water droplets, but the high altitude can be dominated by ice crystals.
These clouds are probably the most popular type. They are easily identifiable through their ‘pile of cotton’ pattern featuring rounded edges that are well-defined. These clouds do not produce rains other than light shower sometimes but otherwise are a sign of fair weather. Cumulus clouds could be found almost everywhere except the polar regions.
To conclude, high-level clouds can form at altitudes of 10,000 to 25,000 ft, whereas the mid-level clouds form at around 6,500 to 13,000 ft. Lastly, the low-level clouds from near the surface up to 6,500 feet. Therefore, the height at which clouds float depends on the type and region since the altitude varies for polar and tropical regions.