Most of the names given to different kinds of cloud simply describe their shapes and positions or give a clue about what we can expect from them. Cirro means “curled”; cumulo means “piled up”; nimbo means “rain”; strato means “in layers or sheets” and alto means “high”. Higher levels of cloud are made of ice crystals. As you might expect, it is the clouds with the word nimbus or nimbo in their names that bring rain, hail or snow. The very lowest clouds drift over high ground as fog.
Clouds are made up of very light water droplets or ice crystals. These particles can float in the air. When warm air rises, swells and cools, it forms clouds. Many water droplets formed together scatter reflect sunlight and you see a white could, but with a dark or gray cloud, the sunlight is scattered in all directions instead of reflected. The different types of clouds are cumulus, cirrus, stratus and nimbus.
Cirrus Clouds
Cirrus clouds are the thin, wispy clouds seen high in the sky. They look as if someone took a cloud, stretched it, pulling pieces off, like a cotton ball when it is pulled apart. They are thin because they are made of ice crystals instead of water droplets. A blue sky and a few cirrus clouds high in the sky, usually means it is going to be a nice day.
Cumulus Clouds
Cumulus clouds are the puffy clouds that are usually scattered throughout the sky. In Latin, the word cumulus means pile. Just like when we say “accumulate,” it means things pile up. This type of cloud is formed when warm air raises carrying water vapor with it by evaporation. Cumulus clouds can be white or gray. White fluffy clouds mean no rain, but when they form into dark or gray clouds, it is going to rain.
Stratus Clouds
Stratus clouds look like a huge thick blanket covering the sky. These clouds are a sure sign of rain if it is warm and snow if it is cold. If stratus clouds are near the ground, they form fog. These clouds form when the weather has been cold and warmer moist air blows in. The amount of moisture in the air and the difference between warm and cold air determine how thick the cloud or fog is.
Nimbus Clouds
The word nimbus means a cloud that already has rain or snow falling from it. These clouds are dark and seen during a thunderstorm along with thunder and lightning. They can be a combination of two clouds, like a cumulonimbus, which means a puffy black cloud with rain falling out or it, or a stratonimbus, which is a dark blanket with rain falling out of it.
Like High-Altitude Fog
Clouds and fog are basically the same things, but most clouds form only at elevation, while fog forms near the ground. Clouds and fog occur because of moisture condensation, but at higher elevations, the water tends to freeze into ice crystals, making high-altitude clouds more reflective and impressive than the ones that form near the ground.
Stratus clouds form at low altitudes and are more closely related to fog than other types of clouds. They aren’t the same as fog, however, because fog usually forms from ground moisture, whereas stratus clouds form from moisture already in the air. They occur when air currents push cold air above a blanket of warm air and moisture quickly condenses. The air currents that form stratus clouds are usually light, and conditions are usually still. The clouds will hang around as long as conditions remain that way.
Just Generally Gray
If you look at the sky on a gray day, you won’t see much definition in the clouds, but if you fly above them, you’ll see that they do have discernible shapes The layer closest to the ground is full of moisture, and the air at the ground may even be misty. That bottom layer usually obscures the shapes of the clouds themselves, but occasionally the mist clears and you can see the clouds. They are generally dense, heavy and large. A single cloud can stretch from horizon to horizon. Because they are so dense, they do a good job of blocking sunlight, so the bottom layer of the clouds – behind the mist – is generally very dark.
Picture Credit : Google
