Southwest Monsoon Expected To Arrive In Kerala By May 31, Says IMD

The IMD forecasted that the Southwest Monsoon is likely to make its onset over Kerala by May 31, with a model error of four days.

The India Meteorological Department (IMD) announced on Wednesday that the Southwest Monsoon is likely to reach Kerala around May 31, heralding the onset of the four-month rainfall season vital for India's agricultural sector.

"This year, the Southwest Monsoon is likely to set over Kerala on May 31 with a model error of dour days," the IMD said. 

IMD Director General Mrutyunjya Mohapatra clarified, "This is not early. It is near the normal date as the normal date for the onset of monsoon over Kerala is June 1."

Last month, the  IMD had projected above-normal rainfall during the June-September Southwest Monsoon season. 

June and July hold significant importance for agriculture as most of the sowing for the Kharif crop occurs during this period. 

Two factors contributing to plentiful rainfall include a positive Indian Ocean Dipole (IOD), which aids in bringing rain to several southern Indian states, and a below-normal snow cover in the northern hemisphere and Eurasia. Historically, a correlation exists between lower snow levels and increased monsoon rainfall. 

Satellite observations have indicated the recognition of cloud bands along the equator, known as the Inter Tropical Convergence Zone (ITCZ), crucial for bringing rainfall over the country during the southwest monsoon season. 

Over the past decade, the monsoon onset over Kerala has occurred in May during the years 2017, 2018, and 2022. 

India experiences southwest monsoon winds in summers and northeast monsoon during winters. Southwest monsoon winds, originating from the formation of an intense low-pressure system over the Tibetan Plateau, bring heavy rainfall to most parts of the country. 

Various factors influence the onset and intensity of Southwest Monssons, including the low-pressure system over the Tibetan Plateau, high-pressure cells in the South Indian Ocean, subtropical jet stream, African Easterly jet, Inter-Tropical Convergence Zone (ICTZ), Somali Jet, Somali Current, Indian Ocean dipole, and Indian Ocean branch of the Walker Cell. 

READ | Tamil Nadu, Kerala, K'taka To Witness Heavy Rainfall, Thunderstorms Till May 18: IMD