Storm is the commotion caused in the atmosphere. It is a severe condition which alters the regular climatic conditions. It causes extreme disruptions such as strong wind (cyclones, hurricanes), snow storm, and ice rain. This unstable weather condition are unpredictable. These winds may become tough when the atmosphere is unstable. Storms leads to dangerous negative impact on buildings, life and other properties.
Cyclones are a type of storm which are nothing but high speed whirling winds. These winds are blowing faster than the regular pleasant breeze. Winds always move from higher pressure area to lower pressure areas. In summer the wind on land is much hotter than that at the sea. So the summer winds moves from land to ocean.
How is a thunder storm formed?
Thunder storm is mainly caused by three ingredients namely
- Moisture- Hazy clouds, high humidity and high pressure in the atmosphere accounts for the storm.
- The increasing instability making atmosphere more buoyant.
- A lifting mechanism such as increasing pressure and heat providing nudge.
The surface of earth is heated and the hot sir moves up. So the air rises from hills, mountains and sea level. This air continue to rise as long as it is hot/warm. As this heat air rises from the earth surface it transfers heat from upper atmospheric levels (known as convention). Water vapour in the atmosphere cools down this heat and condenses to form clouds. The thunderstorm rises up in the air and mixes with the ice particles formed in clouds. As the particles in clouds collide, there will be electrical discharge which results in thunder lightning and hail storm.
Life cycle of a thunderstorm
There are three main stages involved in the life cycle of thunderstorm.
- Developing Stage: This stage is also known as cumulus stage since it is marked by cumulus cloud. The heated air rises from the earth surface. As the updraft continues the cloud looks like a tower, it is also called as towering cumulus cloud. This air cools down in the upper layers of atmosphere and condenses to form cumulus cloud. During this stage the cloud edges are distinct and sharp. This indicates that cumulus clouds. It is made up of water droplets. So once the air rises above freezing level it begins to precipitate.
- Mature stage: Both updrafts and downdrafts is characterised inside the cloud. The down drag falling of precipitation is initiates the downdraft. The evaporative cooling strengthens the downdraft. This downdraft enters the layer of warm air below the cloud and then evaporates. This descending air reaches the ground surface before precipitation. As the thunderstorm develops in the mature stage, the cumulus cloud increases in height, width and size. Heavy rain, hail and tornadoes are likely to appear in this stage.
- Dissipating stage: There is huge amount of precipitation and updraft occurring at the beginning of dissipating stage. When the precipitation in the cloud becomes heavy the decay of thunderstorm is initiated. Since there is no additional heat released after cloud droplet freezes, the cloud begins to collapse. The warm air feeding the thunderstorm is cut off by the gust front which moves long distance. Hereby the intensity of rainfall decreases.