The India Meteorological Department (IMD) announced on Sunday that the Southwest Monsoon has begun, marking its arrival over the Nicobar Islands and the South Andaman Sea. This development is crucial for India’s agriculture and overall economy, making it important to understand what the monsoon is and why it matters.
About Southwest Monsoon
The Southwest Monsoon is a seasonal wind system that brings heavy rainfall to India from June to September. It is crucial for irrigating crops, replenishing water reservoirs, and generating hydropower. This year, the IMD reported that the monsoon has advanced into parts of the Maldives, the Comorin area, the South Bay of Bengal, the Nicobar Islands, and the South Andaman Sea.
Significantly, the IMD announcement follows after conditions were found suitable for the advancement of monsoon, which include, an increase in the strength of Westerly winds in the lower tropospheric levels (upto 3 km) to about 20 knots, prevalence of southwesterly winds up to the height of 4.5 km above mean sea level over the region and an increase in cloudiness.
Meanwhile, the development also follows with an update that the IMD had forecasted above-normal rain in monsoon season. During a presser, Secretary Ministry of Earth Sciences informed that, the rainfall during the 2024 southwest monsoon season from June to September is forecasted to be above normal and higher. Quantitatively it is likely to be above 106% of Long Period Average (LPA). LPA of monsoon rainfall is 87 cm.
Onset in Kerala
With the arrival of the southwest monsoon in the country, the IMD had also predicted its arrival in Kerala by May 31. Typically, the monsoon sets in over Kerala around June 1, with a standard deviation of about seven days. This slightly earlier arrival is expected to benefit the agricultural sector and water resources. Significantly, advance of the southwest monsoon over Indian main land is also marked by monsoon onset over Kerala and is an important indicator characterizing the transition from hot and dry season to a rainy season.
"Southwest monsoon normally sets in over Kerala on June 1 with a standard deviation of about seven days. This year, the southwest monsoon is likely to set in over Kerala on May 31," the IMD said in a release.
It is important to note that after the southwest monsoon normally sets in over Kerala, it advances northwards, usually in surges, and covers the entire country around July.
Relief from Heatwave
Meanwhile, the onset of the monsoon also brings much-needed relief as large parts of India are currently experiencing a severe heatwave. Temperatures have soared up to 48 degrees Celsius, impacting health, water supplies, and power grids. The arrival of the monsoon is expected to alleviate these extreme conditions.
