Southwest Monsoon

These monsoons are also known as southwestern summer monsoons. They occur between the months of July and September. During the Summer times, the Thar desert and central India gets heated up which causes a low pressure to be formed over northern and central India. Due to the low pressure, the moist water vapor-rich air moves towards central and northern India. This moisture-rich air moves toward the Himalayas. The Mighty Mountains act as a barrier and block the paths of these winds. As these winds rise the temperature decreases and causes cloud formation and precipitation. 

Factors that influence the onset of the Southwest Monsoon are mostly intense low-pressure formation over the Tibetan Plateau, permanent high-pressure cells in the South of the Indian Ocean, subtropical jet stream, African Easterly Jet, and Inter- Tropical Convergence Zone.

They generally start at the beginning of July and end towards the end of September. When they reach the last point in its path they are divided into two parts the Bay of Bengal Branch and the Arabian Sea Branch. This specific monsoon accounts for around 80 percent of the total rainfall in India. The agricultural sector in India is highly dependent on this monsoon. This monsoonal rainfall is a by-product of air passing over large areas of the warm equatorial ocean, stimulates increased evaporation, cools as it moves north and as it rises over the land; as at some point it is not able to retain moisture and precipitation starts, used for irrigation of rice fields and drench rainforests, sometimes even leading to floods.

Monsoon can be defined as the change in the direction of winds and currents in a region, leading to the formation of clouds and precipitation. Monsoon is a seasonal phenomenon. The monsoon winds generally blow from cold to warm areas. The monsoon in Asia can be classified into Southwest Monsoon and Northeast Monsoon.

India receives Southwest monsoon winds in summer and Northeast monsoon during winter. The Southwest monsoon arises because of the formation of an intense low-pressure system over the Tibetan plateau. The Northeast monsoon arises due to high-pressure cells that are formed over the Siberian and Tibetan plateaus.