A day after the weather department came under a lot of fire over its prediction with regard to the onset of monsoon this year, the India Meteorological Department (IMD) on Tuesday clarified that monsoon rainfall during the next four months (June to September) is likely to be “normal” at 103% of long-period average (LPA), with a model error of +/-4%. The IMD made the observations while presenting its second stage long-range forecast (LRF) for monsoon on Tuesday.
“The southwest monsoon seasonal rainfall over the monsoon core zone, which consists of most of the rainfed agriculture regions is most likely to be Above Normal (>106% of LPA),” according to the IMD.
A controversy has broken out over the India Meteorology Department (IMD) declaring the onset of the South-West monsoon on Sunday (May 29), with top officials in the government wondering if the set norms for such a declaration have been followed.
Addressing a press conference, IMD’s Director General Dr Mrutyunjay Mohapatra said that the average rainfall this monsoon season is expected to be 103 per centof the long period average. “ Normal or above normal rainfall is most likely over many parts of northwest & central India, northern parts of South Peninsula and some parts of east India. Below normal rainfall is most likely over many parts of northeast India, some pockets of central & east India and southern parts of south peninsular India,” he said.
The monsoon core zone - states ranging from Gujarat to Odisha that are dependent on rainfall for agriculture - is set to experience above normal rainfall at more than 106 per cent of the long period average, Mohapatra said.
If realised, 2022 could become the fourth consecutive year when India will receive normal monsoon rainfall. Effectively, it has been upgraded from 99 per cent as stated earlier by IMD in the first stage LRF released in April this year. Starting this year, the IMD is following the downgraded seasonal LPA value of 87 cm.
Earlier, India had witnessed normal monsoon from 2005-08 and 2010-13. Mohapatra said in the near future, India could witness normal monsoons as the decadal epoch of below normal rains was nearing its end.
Asked about the criticism faced by IMD for "hasty" declaration of monsoon onset over Kerala, Mohapatra said the weather office followed a scientific process to announce the onset and progress of monsoon. He asserted that 70 per cent of the weather stations in Kerala had reported fairly widespread rainfall and other parameters related to strong westerly winds and cloud formation over the region were fulfilled.
Mohapatra said the prevailing La Nina conditions, which refer to the cooling of the equatorial Pacific region, were expected to continue till August and augur well for the monsoon rains in India.
However, the possibility of development of negative Indian Ocean Dipole, which refers to cooler than normal sea surface temperatures in the western Indian Ocean, could lead to below normal rainfall in extreme southwestern peninsula that includes Kerala.