A thunderstorm is an intense atmospheric circulation associated with large, dense cumulonimbus clouds in which there is a strong upward movement of air. Thunderstorms cause heavy downpours, and therefore, they are called ‘cloud bursts,’ but the rainfall is of a very short duration. This article will help you understand thunderstorms and how they form due to updrafts and downdrafts. It also discusses briefly the three stages of thunderstorms, namely the cumulus stage, the mature stage, and the dissipating stage. Aspirants preparing for the UPSC IAS Exam will find this article extremely useful.
A Thunderstorm consists of several convective cells characterized by strong updraft air. Each cell passes through a life cycle. These phases of the life cycle consist of youth, maturity, and the old stage.
|First Stage||It is the cumulus stage when warm air rises strongly upward and helps in the formation of clouds.|
|Second Stage||It is a mature stage characterized by both the upward and downward movement of winds and the occurrence of rainfall.|
|Third stage||The third stage is dissipating stage, characterized by the downward movement of winds that spread over the ground surface and stop the vertical movement of winds.|
Read More: Types of Winds
Here is an illustration of various stages in the development of thunderstorms.
Read More: List of Major Local Winds
Thunderstorms are caused by Cumulonimbus Clouds, which form when there is a rapid rise or movement of warm and moist air. Cumulonimbus clouds can form at heights of more than 20 kilometres and are formed by the upward movement of warm, moist air. When warm, moist air rises, it cools and condenses, resulting in the formation of cumulonimbus clouds. When rising air reaches its dew point temperature, water vapour condenses into water droplets or ice. This causes a local decrease in pressure within the thunderstorm cell.
Any precipitation that falls through the clouds travels a long distance to the Earth’s surface. When the smaller droplets that are falling down collide with other droplets, larger droplets form. The falling droplets cause a downdraft by pulling cold air with them, and this cold air spreads out over the Earth’s surface. This causes the strong winds that are common during thunderstorms.
Thunderstorm and Weather
Surface heating through intense insolation, mainly during summer on land surfaces, causes a convective mechanism resulting in an updraft of air and condition for precipitation.
Rainfall is in the form of a heavy downpour with the greatest intensity of all other forms of precipitation but of short duration.
When condensation occurs below the freezing point, ice particles of big size are formed. Not every thunderstorm produces hail. Hail falls on the ground surface when they are capable of overcoming the force of rising convection currents.
Electric discharge centres are developed in a mature thunderstorm. Positive and negative electric charges develop in the upper and lower portions of clouds. Lighting is produced when the electrical potential gradient between the electrical charges becomes steep.
Sound is produced due to the sudden and rapid expansion of air columns caused by intense heat resulting from lightning strokes.
Read More: Types of Clouds
Are Thunderstorms Dangerous?
- Thunderstorms and the phenomena that accompany them can pose a number of hazards to people and the environment. Thunderstorms are usually the cause of flash floods and large hailstones.
- Every year, flash floods kill more people than hurricanes, tornadoes, or lightning.
- Thunderstorm cells that are more powerful produce tornadoes and waterspouts.
- Every year, lightning causes many fires around the world and kills people.
- Hail up to the size of softballs can cause extensive damage to vehicles and even kill livestock if they are not protected.
- Strong winds associated with thunderstorms cause damage to trees, power lines, and a variety of public properties.
- Tornadoes with speeds of up to 300 miles per hour can destroy everything, sparing only the best-built man-made structures.
Read More: Types of Rocks
- Tornadoes and thunderstorms are severe local storms. They are brief and occur over a small area, but they are violent.
- A thunderstorm is a storm that includes thunder and lightning, as well as heavy rain or hail.
- Thunderstorms are most common when the temperature is high. Because of the cold, thunderstorms are less common in bodies of water.
- Every year, an estimated 16 million thunderstorms occur worldwide, with approximately 2,000 thunderstorms active at any given time.