Table of Contents
This is not common rainfall after giant flashes and sounds rumbling and booming. What causes these giant flashes and thunder crashes? Basically, thunderstorm is merely a storm containing lightning and thunder. Thunderstorm may produce winds accompanied by heavy rain and hail (Merkel and Monahan 2008). Some people have the belief that thunderstorm occurs when a man and woman who live in heaven starts to fight. During their fight they throw pots, utensils and other items to each other. The sound made by these pots and utensils is what is called a thunderstorm. However, this is just a belief and therefore this paper will clearly explain how thunderstorm is formed (Lutgens and Tarbuck 319).
Mostly, thunderstorms form during the day after the sun warms the air. The air contains a lot of water vapor and therefore as the water gets warm, it rises into the sky. This water vapor rises higher and higher. As the water vapor rises through the air to the sky, it comes into contact with dust thus mixing with it (Merkel and Monahan 2008). This mixture of dust and water vapors results to formation of clouds. Depending on the amount of the dust and water vapor, some clouds can grow as big as a giant with flat and wide tops. These big clouds are known as anvil clouds. The anvil clouds show that rain is about to fall (Lutgens and Tarbuck 319). The clouds pile up, grow thick and dark. They also contain so many water droplets and thus they block out the sunlight. As the droplets cool off, they grow in size and also stop rising. Some of these drops fall back to the ground as they carry cool air with them. The cool air falling down from the sky is known as downdraft (Lutgens and Tarbuck 319).
Storm cells and super cells
Storm cell is formed by falling cold air and rising air. A thunderstorm is formed by one or more of these storm cells. After the water droplets formed in the storm cloud turn into rain, the drops fall as rain. This makes the storm cell to reduce in size and slowly the storm starts to die. In most cases, thunderstorm last for about thirty minutes (Merkel and Monahan 2008). Sometimes super cell can last for several hours. This happens when very cold air and wind makes a storm cell to grow very big. This results in many cells swirling and gathering together to form one super cell thunderstorm (Lutgens and Tarbuck 319). These super cell thunderstorm are accompanied by thunder and lighting, pouring rain and very strong winds.
Stages in thunderstorm development
Development of thunderstorm occurs in three distinct steps.
Cumulus clouds can be defined as full clouds which are big and white in color and are mostly present when the weather is calm (Merkel and Monahan 2008). The first stage in thunderstorm formation is cumulus cloud although most of them do not become thunderstorms. In this stage there is rising current of air in the storm cell which may vary depending on whether the cell is mature or not. As the air current continues to rise in the cell, the water droplets grow big in size and this result to formation of raindrops.
This stage consist of surface rain and upward and downward air currents. At this time the average storm cell has grown very big. As the drops start to fall, a downward air current is formed. This descending air gets colder than the environment around and this downward motion increases thus forming downward air current. This air current reaches its maximum speed shortly after the rain starts to fall. Downward flow of air current takes place at all stages during a storm formation but the speed differs (Lutgens and Tarbuck 319).
In the entire life of the mature cell, more and more air is entrained by the falling raindrops (Lutgens and Tarbuck 319). Consequently, the downward air current spreads thus replacing the weakling upward air current. As this process continues, the whole lower part of the cell is occupied by the descending air current. Rising air current is important in causing condensation and releasing heat energy. Therefore, the whole structure starts to disperse. Strong winds move the upper part of the cloud into a familiar anvil form. However, the presence of the anvil does not always indicate that the thunderstorm will disperse (Lutgens and Tarbuck 319).
Thunderstorms may take place in any type of cloud whether warm, cold or stationary. Some thunderstorms are caused by rising of warm, moist and unstable air in the cloud surface. Some may also occur in a quick moving cloud and are known as squall line thunderstorm. Warm thunderstorms may occur when warm, moist and unstable air is forced over cold, denser and retreating air (Lutgens and Tarbuck 319).
The basic factors that are essential for the formation of a thunderstorm include unstable air which contains high moisture and some lifting action. Lifting of warm air may not necessary cause free heat movement (Merkel and Monahan 2008). This is because the air may be lifted to a point where the moisture condenses and clouds are formed. These clouds formed however may be stable if the level of heat movement will not have been reached by the lifting. Conversely, it is possible for dry air which is heated to rise and fail to form clouds.