New Delhi: Several parts of the country are suffering from an early heatwave, but India, overall, is expecting a “normal” monsoon this year, the Met department said. “There’ll be a normal monsoon this year in India as across the country there’ll be 99% of rainfall,” Mrutyunjay Mohapatra, Director General of Meteorology, IMD said.
He added, however, that some parts of the country can get below normal rainfall. “As per the prediction, there’ll be a uniform distribution of rainfall. For the Northeast, Kerala, Tamil Nadu, J&K and parts of Punjab, Haryana & Himachal Pradesh, rainfall could be below normal,” the IMD DG was quoted by ANI.
Meanwhile, the weather office on Thursday (April 14) had introduced a new all-India rainfall normal – 868.6 mm – for the southwest monsoon based on the data from 1971 to 2021, which will be used as the benchmark to measure rainfall in the country. The new rainfall normal, rounded off at 87 cm for the southwest monsoon season, is a marginal decline from the previous “normal” of 88 cm which was calculated on the basis of rainfall data from 1961-2010, Mrutyunjay Mohapatra said.
The IMD issues weather forecasts and summaries in terms of departures from the normal, which is a long period average (LPA) of rainfall received over a 50-year period. The ‘normal’ rainfall or the LPA is updated every 10 years. “Presently the southwest monsoon is passing through a dry epoch which started in the decade of 1971-80,” he said. According to Mohapatra, the decadal average of all India’s southwest monsoon rainfall for the 2011-20 decade is minus 3.8 per cent from the long-term mean.
“The next decade i.E. 2021-30 will come closer to normal and the southwest monsoon is likely to enter into the wet epoch from the decade of 2031-40,” he said. The new all India annual rainfall normal, based on the 1971-2021 data, has been fixed at 1160.1 mm compared to the earlier normal of 1176.9 mm based on the 1961-2010 data.
Southwest monsoon rainfall, spread across the months of June-September, contributes 74.9 per cent to the annual rainfall, while the pre-monsoon rains – March-April-May – contributes 11.3 per cent. Post monsoon rainfall – October, November, December – contributes 10.4 per cent to the annual rainfall, while winter rains in January and February contribute 3.4 per cent to the yearly rainfall.
The new rainfall normal has been computed using rainfall data from 4,132 rain gauge stations distributed across 703 districts of the country.
(With Agency inputs)
