Monsoon rains from June to September are likely to be more than that anticipated by the India Meteorological Department (IMD) in April, with the agency on Tuesday upping its estimate from 99% to 103% of the Long Period Average (LPA).
The monsoon rains over the four broad regions — central India, southern peninsula, northeast India and northwest India — for which the IMD provides a forecast, are also likely to be plentiful. Central India and the southern Peninsula are expected to get 106% of their historical average. Rainfall is likely to be ‘normal’ over northeast India and northwest India.
The southwest monsoon seasonal rainfall over the monsoon core zone, which consists of most of the rainfed agriculture regions, is also most likely to be ‘above normal’ or more than 106% of its historical average.
M. Mohapatra, Director General, IMD, told The Hindu that the expectation of increased rains was largely premised on La Nina conditions prevailing through the monsoon month. In April, it was expected that the ongoing La Nina conditions would transition to neutral conditions. La Nina is the converse phenomenon of the El Nino and is characterised by a cooler than normal sea surface temperatures in the central Pacific.
“Along with La Nina, we expect other meteorological factors to be favourable too,” Dr. Mohapatra said. An influential factor called the Indian Ocean Dipole is expected to be negative and is considered not favourable for the monsoon. “Other factors are expected to compensate and that’s why we expect the monsoon rains to be within the normal range of 96-104% of the LPA,” he added.
The most important monsoon months, for agriculture, are July and August though the IMD is expected to announce the forecast for July only by the end of June. Were monsoon rains to be normal this season, it would be the fourth consecutive year of ‘normal’ or ‘above normal’ rainfall.
Last year, India received 99.3% of the average rainfall. In 2020, India received 109% of the average, and in 2019, 110%. Not since 1996, 1997 and 1998 has India got three consecutive years of ‘normal’ or ‘above normal’ rain. Historical trends suggest that the Indian monsoon passed through ‘epochs’ or roughly three decades of subdued rainfall and three of heightened rainfall. “India is currently exiting an epoch of reduced rainfall and entering a heightened one. So this [expectations of normal monsoon in 2022] could be part of this change but beyond that, we don’t know if they are other factors responsible,” Dr. Mohapatra said.
The ‘normal’ monsoon rains don’t imply that all months would see well distributed rains. In 2021, for instance, August stared at a 24% deficit but September, usually the month that sees the least rainfall, saw excess rains, similar to what was observed in 2019 and 2020.
Monsoon rains from June-September are likely to be more than that anticipated by the India Meteorological Department (IMD) in April, with the agency on Tuesday upping its estimate from 99% to 103% of Long Period Average (LPA).
