Information About the Cirrostratus Clouds

Contrails, the artificial clouds formed behind the aircraft, may persist for several hours, resembling the cirrostratus clouds.

Cloud watching is fun, especially when you start recognizing its shapes and types. They seem like fluffy, white cotton balls floating in the sky. The clouds often take the shape of animals, birds, and all other things that you can imagine. They are one of the most incredible phenomena of nature.

Though all clouds might seem the same to you, they are classified according to their shapes, altitudes, size, etc.

One of the types is the cirrostratus cloud. The name Cirrostratus comes from a Latin word, meaning 'curl and spread out', or 'curl' and 'layer' that perfectly describes how these clouds appear in the sky. They are the sheet-like thin, high-level clouds that are difficult to recognize.

They are composed of ice crystals because of their high altitude, and can cover the entire sky rather than being concentrated on just one place.

Clouds are classified according to the heights at which they are usually formed, low, middle, or high. Cirrostratus clouds are high-level clouds that form at around 20,000 - 42,000 feet above sea level. They have similar features as that of Cirrus clouds, but are more widespread and darker.

They are horizontally layered and vary in thickness. Their colors range from light gray to white. The edges of this cloud are uneven. However, sometimes they may appear to be clean or straight. The large ice crystals that are formed give the cloud a fibrous effect.

They can be seen anywhere around the world. One of the best features of this cloud is that they can be carried long distances and span thousands of miles from where they are formed. They typically move along the direction of the wind, mostly in a westerly direction. However, it varies according to latitude, weather conditions, and time of the year.

And when the sunlight or moonlight shines through these clouds, a halo effect is created. It is caused because the light gets reflected off the ice crystals, which make up these clouds. They can be several feet deep, yet relatively transparent for the sun or moon to be seen through them.

Cirrostratus clouds are formed mostly during a peaceful weather. They are formed about 12-24 hours before precipitation i.e., just before rain or snowstorm. However, they only represent the warm front coming in and do produce precipitation. This may be an indication that you should be ready with your jackets and raincoats unless you want to get drenched.

The cirrostratus clouds are usually formed by spreading and joining of the cirrus clouds. The cloud formation usually occurs when cool, dry air meets the warmer, moist air.

And when the sunlight or moonlight shines through these clouds, a halo effect is created. It is caused because the light gets reflected off the ice crystals, which make up these clouds. They can be several feet deep, yet relatively transparent for the sun or moon to be seen through them.

These clouds are formed in the following manner:

• The lighter winds at ground level drive the water particles into the atmosphere.
• The steady and concentrated warmer air move the water particles into the upper atmosphere. There shouldn't be any intervening cloud layers to stop the rising water particles.

When the warm front arrives (slow decline in air pressure), the clouds start forming at about 18,000 feet upwards because of crystallization of water particles.

• Cirrostratus fibratus (Cs fib) that means fibrous veins. These clouds are fibrous and have a patchy appearance. They are mostly surrounded by cirrus clouds.
• Cirrostratus nebulosus (Cs neb) that means smooth and fog-like veil. Their appearance is unchanging and are mostly responsible for creating halos around the sun or moon.

The sub-species of this cloud are:
Cirrostratus undulatus (Cs un) that means veil with wave formations. These clouds are usually distinguishable because of their wavy ripples.
Cirrostratus duplicatus (Cs du) that means two or several layers lying on one another. These clouds have more than one layer.

When the sun is low enough on the horizon, cirrostratus clouds can be seen in a magnificent display of colors like red, yellow, and orange. This happens because the longer wavelengths of sunlight get reflected off the clouds. So, now you know what you'll be looking at next time you spot a halo or a yellow/orange colored sky with light clouds.