Southwest Monsoon Withdraws From India
Context
The northeast monsoon is expected to arrive “in the next 72 hours,” according to the India Meteorological Department (IMD), which declared the end of the southwest monsoon on Thursday.
What are the monsoon conditions in India?
- India’s southwest monsoon, which marks the change from the wet to the dry season, has concluded.
- The northeast monsoon, sometimes referred to as the “retreating monsoon,” is predicted to arrive within the next 72 hours, according to the India Meteorological Department (IMD).
What is the South West Monsoon in India?
- The southwest monsoon is a seasonal wind that brings rain to India from the Arabian Sea. It takes place from June to September. India receives most of its rainfall from the southwest monsoon.
- The reason for the southwest monsoon is:
- the Indian Ocean’s high pressure
- warming of the Indian Ocean’s tropical coastal waters
- A high-pressure area is present to the east of Madagascar.
- The Plateau of Tibet
- The westerly jet’s movement
- flows southwest from the Arabian Sea to the Indian continent.
- delivers comparatively light rains to the rest of India and extremely heavy rainfall to the west coast
- Usually starts around the start of June and ends at the end of September.
- divides into the Arabian Sea Branch and the Bay of Bengal Branch upon reaching the southernmost point of the Indian Peninsula.
Which areas receive the South Monsoon rain?
- The coastal state of Kerala, India, receives rains from the Southwest Monsoon first in the Arabian Sea Branch, which first reaches the Western Ghats in this region.
- With precipitation on coastal areas west of the Western Ghats, this monsoon branch flows northward along the Western Ghats (Konkan and Goa).
- Because the wind does not traverse the Western Ghats, the eastern parts of the region receive little rain during this monsoon.
What is the Northeastern Monsoon?
- The Indian subcontinent’s climatic system is mostly influenced by the Northeast Monsoon, sometimes referred to as the retreating monsoon. It happens in October and November.
- The winds from the northeast to the southwest are what define the Northeast Monsoon. Moisture from the Indian Ocean is carried by these winds. They carry moisture from the Bay of Bengal, which they disperse throughout areas of Sri Lanka and the Indian peninsula.
- The Northeast Monsoon is influenced by global climate parameters such as:
- ENSO (El Nino/La Nina & Southern Oscillation Index – SOI)
- Indian Ocean Dipole (IOD)
- Madden-Julian Oscillation (MJO)
- During the winter, high-pressure cells form and get stronger over the Tibetan and Siberian Plateaus.
- The Inter-Tropical Convergence Zone’s (ITCZ) movement or migration south of India
- The southern Indian Ocean’s high-pressure cells are moving westward and becoming weaker.
Which are the areas that get rain due to the North-East Monsoon?
- While the majority of India’s rainfall comes from the southwest monsoon, Tamil Nadu, south-inner Karnataka, coastal Andhra Pradesh, Rayalaseema, Puducherry, and Kerala receive significant amounts from the northeastern monsoon.
What is the withdrawal timeline predicted by the IMD?
- In Rajasthan, the southwest monsoon usually begins to depart in late September.
- The southwest monsoon doesn’t completely go until early to mid-October, at which point the northeast monsoon takes its place.
How much rain did India receive from the monsoons?
- 94% of the precipitation predicted for the four monsoon months has already fallen in India as of September 30.
- Although this 94% is within the IMD’s forecast models’ error tolerance, it is just less than the 96% prediction.
- 96% to 104% of the long-term average rainfall is regarded as “normal.”
- August was dry due to an El Nino event, which had an impact on the monsoon’s overall performance.
- However, September’s higher-than-expected rainfall helped to partially offset August’s dry spell.
What is the significance of the Northeast Rain?
- In India, 11% of the yearly rainfall is due to the northeast monsoon. Only five states in South India are impacted by the northeast monsoon, with Tamil Nadu receiving the most rain. Another name for the northeast monsoon is Amihan.
- The reason the northeast monsoon matters is that it
- brings rain to the coast of Coromandel
- causing rainfall in interior districts due to wind convergence when the southwest and northeast monsoons are changing.
- clouds up over the Bay of Bengal, bringing with them moisture and precipitation.
