IMD predicts above normal monsoon for 2024

Neutral El Nino conditions during the early part of the monsoon, followed by the setting in of La Nina by August-September, will likely result in above-normal monsoon in 2024, the Indian Meteorological Department (IMD) has predicted. An analysis for the period 1951 to 2023 also shows that La Nina during the later part of the monsoon is mostly positive for rainfall.

“We have done a study for the period between 1951-2023 and found that out of 22 La Nina years in that period except two – 1974 and 2000 – all other years have recorded above normal or normal monsoon,” said Dr. Mrutyunjay Mohapatra, director general of meteorology, IMD, on Monday. Besides, he added, “India experienced above-normal rainfall in the monsoon season on nine occasions when La Nina followed an El Nino event.”

“That is the reason why the south-west seasonal (June to September) monsoon as a whole is likely to be above-normal with rainfall estimated at 106 per cent of the long-period average (87 cm).”

At present, neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean and the latest forecasts indicate that the conditions would be positive for the monsoon.

The below normal snow cover over Europe and Eurasia this spring also points to the direction that the monsoon in India would be good. “Snow cover over the northern hemisphere this spring was below normal. That has an inverse relationship with south-west monsoon rainfall hence above normal rainfall is expected,” Mohapatra added.

Most of the rainfall in India occurs as a result of the south-west monsoon except in Tamil Nadu, which falls under the influence of the north-east monsoon. Although the IMD has predicted above normal cumulative rainfall, it does not guarantee uniform temporal and spatial distribution of rain across the country with climate change further increasing the variability with precipitation highly variable both in time and space. According to estimates, more than 50 precipitation takes place in about 15 days and less than 100 hours altogether in a year.

India received "below-average" cumulative rainfall — 820 mm compared to the long-period average of 868.6 mm — in 2023, an El Nino year. Before 2023, India recorded "normal" and "above-normal" rainfall in the monsoon season for four years in a row. El Nino conditions — periodic warming of surface waters in the central Pacific Ocean — are associated with weaker monsoon winds and drier conditions in India.

Meanwhile, the IMD cautioned against heat wave conditions forming over West Bengal, Andhra Pradesh, Tamil Nadu, Telangana, Odisha and Goa in the coming week. “We are constantly sharing the weather forecast with the Election Commission and other relevant agencies about state-specific updates,” IMD added.