India to witness normal monsoon; 98% of average rainfall

Amidst the Covid-19 gloom, the India Meteorological Department (IMD) on Friday announced a “normal monsoon” this year in which India is expected to receive 98 per cent of the average monsoon rainfall, raising the hopes of better farm productivity.

“The 2021 south-west monsoon season will be a normal one with the expectation of 98 per cent of the LPA. There is a 40 per cent probability of normal rainfall (96-104 per cent), which is the highest probability among all the categories. It's good news for agriculture output,” M Rajeevan, Secretary, Ministry of Earth Sciences said in a briefing.

India’s long period average rainfall is 88 cm, which is the average rainfall the country had received during the four-month-long monsoon season between 1961 and 2010. The hopes for a normal rainfall have been further boosted due to the absence of the dreaded El Nino factor that affects the Indian monsoon adversely.

All climate models currently show an ENSO (El Nino Southern Oscillation) neutral conditions after May, which means there would be no El Nino threat — an unusual rise of the Pacific temperature, which in turn plays havoc with the weather systems around the world. The previous year (2020) saw La Nina conditions — cooling of the Pacific and beneficial to Indian Monsoon — which is expected to continue till May end after which the ENSO neutral conditions are likely to set in.

Historically, there have been 14 La Nina years since 1951, of which the monsoon rainfall was normal in 11 cases. Out of the three remaining years, two were El Nino years. However, Rajeevan and IMD director general M Mahapatra warned of below normal rainfall for east and north-east India. “It may be a case of decadal variation that eastern India is receiving less rainfall in recent years,” Rajeevan told DH.

Next month, the weather office would update its monsoon forecast with specific predictions for four broad homogenous regions besides the overall forecast. For the first time, it would also offer a forecast of the monsoon behaviour in its “core zone”, a vast area spanning over central and western India, which is associated with 88 per cent of monsoon variability and holds key to the monsoon’s “break phases”..