The winds of the southwest monsoon arrived over Kerala and advanced into many regions of Northeast India on May 30, a day earlier than predicted by the India Meteorological Department (IMD). The monsoon usually strikes the state on June 1.
Both Kerala and Northeastern states are currently under a rainfall spell, which may continue. The rainfall in Kerala is due to a long-lasting cyclonic circulation over the region and in the Northeast due to the remnants of Cyclone Remal.
The IMD has said in its second long range forecast that India may receive 106 per cent of its long period average (LPA). LPA is the average monsoon rainfall from 1970 to 2020. IMD categorises this rainfall as ‘above normal’.
IMD expects ample rainfall for most of India’s geographical regions except the Northeastern states, extreme north of northwest and eastern parts of central India.
Rainfall in Northeast India would be below 94 per cent, which is categorised as 94 per cent. IMD predicts above normal rainfall (>106 per cent) over southern and central India and normal rainfall over the northwest.
Rainfall over the core monsoon zone, which is mainly rain-fed, is also expected to be above normal.
IMD has predicted above normal rainfall for India during the southwest monsoon because of myriad factors.
The first of these is the possible development of a La Nina phenomenon in the equatorial Pacific Ocean during July to September, which is generally responsible for more rainfall over India during the monsoon.
The second reason is the possible development of a positive Indian Ocean Dipole which is also conducive for rainfall over the country. The third reason is the decrease in snowfall over the Northern hemisphere, especially in Eurasia, during the winter and spring months of 2024.
The deceased snowfall over the region has an inverse relationship with monsoon rainfall over India. On the other hand, increased rainfall — especially in the latter part of the monsoon when the La Nina is to develop — may also mean increased frequency of extreme rainfall events and consequent floods in the plains and flash floods and landslides in the hilly areas.