Monsoon rainfall over the country is likely to be normal —101% of long period average (LPA), India Meteorological Department (IMD) said in its second-stage long range forecast for the country released on Tuesday.
The LPA is measured from 1961 to 2010, and is 88cm. In 2021, there is a 40% probability that monsoon rain over the country is likely to be 96% to 104% of LPA. This is an upgrade, since IMD’s first-stage monsoon forecast issued in April which said monsoon rain is likely to be 98% of LPA.
Northwest India is likely to record 98% to 108% of LPA; central India is likely to record above normal rain over 106% of LPA; the south peninsula is likely to record between 93% to 107%; northeast India is likely to record below normal rain at less than 95% of LPA.
For the first time, IMD issued a special forecast for the monsoon core zone stretching from Odisha to Maharashtra and Gujarat, where agriculture is largely rain-fed. In the monsoon core zone, monsoon rain is likely to be above normal—over 106%.
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Monsoon rainfall is likely to be well distributed spatially across the country also, IMD said. “Most parts of the country are expected to receive normal to above normal rainfall during the season,” IMD said in its press statement.
There is likely to be normal to above normal rain in June at 92% to 108% of LPA. The spatial distribution suggests above normal rainfall probability is likely over most areas of eastern parts of central India, along the planes of Himalayas and east India. Below normal probability is likely over many areas of northwest India and southern parts of south peninsula and some areas of northeast India.
La Niña conditions turned to neutral in April-end according to IMD. El Niño Southern Oscillation (ENSO) neutral conditions are likely to continue over equatorial Pacific Ocean through monsoon.
The 2020-2021 La Niña event has ended and neutral conditions (neither El Niño nor La Niña) are likely to dominate the tropical Pacific in the next few months, World Meteorological Organization (WMO) also said on Tuesday. Air temperatures are expected to be above average between June and August, especially in the northern hemisphere. There is very little chance of El Niño conditions developing now.
ENSO is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean according to the National Oceanic and Atmospheric Administration (NOAA).
ENSO has a major influence on weather and climate patterns such as heavy rains, floods and drought. El Niño has a warming influence on global temperatures, whilst La Niña has the opposite effect. In India for example, El Niño is associated with drought or weak monsoon, while La Niña is associated with strong monsoon and above average rains and colder winters.
Speaking about the delayed monsoon onset compared to IMD’s onset forecast date of May 31, M Mohapatra, director general, said, “The monsoon is a dynamic system. On May 15, we had said its onset is likely around normal date of June 1. But the criteria for declaring monsoon were not fulfilled. Now conditions are very gradually becoming favourable, and we are expecting the onset of monsoon around June 3.”
The Monsoon season, which begins on June 1, is crucial for summer crops and brings about 70% of India’s annual rainfall. It is critical to the country’s agriculture, which is one of the mainstays of its economy. Monsoon spurs farm produce and improves rural spending. It is the lifeline for about 60% of the country’s net cultivated area, which has no irrigation. The monsoon impacts inflation, jobs, and industrial demand. Good farm output keeps a lid on food inflation. Ample harvests raise rural incomes and help inject demand into the economy.
Nearly half of India’s population depends on a farm-based livelihood. The rains also replenish 89 nationally important reservoirs critical for drinking and power generation.