Clouds come in different shapes and sizes. Did you know that there are clouds in the shape of an anvil? Strange and unusual, isn’t it? Those are cumulonimbus clouds for you! This ScienceStruck article takes you through some facts, description, and formation of cumulonimbus clouds.
Did You Know?
A single cumulonimbus cloud has as much energy as 10 atom bombs would have, and it can hold up to half a million tons of water.
Ever looked up in the sky and tried tracing out some wonderful patterns and shapes of clouds that keep changing every few seconds? Some take the shape of an animal, some of birds, and all others that you can think of. They surely get your brains ticking and exploit your imagination. They can be really fascinating and mesmerizing at times, and make you wonder in awe about the magical phenomena of nature. Doesn’t it make you curious about their formations and shapes?
Clouds are large masses of tiny water droplets (vapors) or ice crystals covered in microscopic dust particles that float in the atmosphere. They shower us with the necessary rainfall that is one of the most important factors for our sustenance on this planet. They are classified as per their appearance and mainly altitudes. Talking about the appearance and altitudes, the most gigantic and king of clouds is the cumulonimbus cloud. By now, you may already be having a question in mind―do cumulonimbus clouds form tornadoes? Yes, they do! Read below to know how.
Cumulonimbus comes from Latin words cumulus meaning heap and nimbus meaning rainstorm or storm cloud. It is often accompanied by lightning, thunderstorms, and severe tornadoes. They are also called thunderheads because of their unique shape. They are low- to middle-level clouds that rise up to as high as 14 miles. They are the largest of all clouds, which are formed from cumulus clouds, and are the base for tornadoes.
Cumulonimbus clouds are large, fluffy, and mighty clouds that take the shape of an anvil or a huge mushroom at the top when well-developed. They are very dense clouds that soar up to a height of about 15 – 22 km. The anvil or mushroom shape is caused due to the strong wind shear or warm air turbulence when the cloud reaches the troposphere. The lightning coming from the flat top is called anvil lightning. Extreme and sudden changes in pressure can result in rotations, causing severe and destructive tornadoes. They can be seen single or in groups, and mostly in tropical or temperate areas. The central plains in the USA are often called ‘Tornado Alley’, and during the rainy season, Florida encounters tornadoes almost daily. They have the potential to grow and form a Supercell cloud, which can be the most rigorous of thunderstorms.
How Do Cumulonimbus Clouds Form?
There are three stages in the formation of cumulonimbus clouds.
- Cumulus or Developing stage
- Mature Stage
- Dissipating stage
Cumulus cloud is the base of formation of a cumulonimbus cloud and also of tornadoes. They are formed when warm, moist air rises within the cooler air. The moisture rapidly cools down and condenses to form tiny drops of water, forming the rising cumulus clouds. It continues to rise, gradually going above the freezing point where exist the tiny droplets and ice crystals. This results in precipitation as soon as it rises above the freezing point. Through the convection precipitation, the air tends to rise in an updraft, resulting in the creation of a low-pressure zone below the developing thunderstorm.
It is a stage of severe thunderstorms and Supercell tornadoes. The clouds in this stage experience both downdrafts and updrafts. The downdrafts are due to the falling precipitation. Cumulus clouds continue rising in shape, height, and size. The lower levels of clouds mostly consist of water droplets. At higher altitudes, the ice crystals are in abundance because the temperatures are below the freezing point. At this point, there can be drastic air turbulence, leading the cloud to flatten out at the top and finally manifesting as lightning, thunderstorms, and tornadoes. The direction of the anvil cloud indicates the direction of the movement of tornado. Cumulus clouds are capable of quickly developing into large cumulonimbus clouds, resulting in powerful thunderstorms and Supercells.
In this stage, clouds experience downdrafts throughout. The thunderstorm is short-lived if the atmospheric conditions are not favorable. It may last for about 25 – 30 minutes. The cloud starts to spread out when the cooled droplets freeze and overpower the updraft. They contain ice crystals, and it first appears in the anvil. The clouds start collapsing as there is no release of latent heat due to freezing of the water droplets. The source of moisture gets cut off, and the rising of clouds ceases. This results in the decay or collapse of a thunderstorm or tornado.
Species of Cumulonimbus Clouds
Other species of cumulonimbus clouds include:
- Cumulonimbus calvus
- Cumulonimbus capillatus
- Cumulonimbus pannus
- Cumulonimbus praecipitatio
- Cumulonimbus velum
- Cumulonimbus virga
Cumulonimbus clouds are a perfect example of how different altitudes influence the formation of clouds at different stages. So, the next time you spot a mushroom- or anvil-shaped cloud, you will surely recognize them. On second thoughts, may be you should try cloud watching as a new and unique hobby. What say?