Weather / Monsoon withdrawal in 2021 will be second-most delayed in 41 years: IMD

New Delhi: The withdrawal of the monsoon this year will be the second-most delayed in 41 years, the India Meteorological Department said on Thursday even as it predicted a normal northeast monsoon this year.

It also put out numbers for the June-September monsoon rains, showing that overall rainfall has been 87.0 cm against a long period average of 88.0 cm based on data of 1961-2010 (99% of LPA). According to the IMD, the monsoon was normal over northwest India (96%); central India (104%); below normal over east and northeast India (88%) and above normal over the southern peninsula (111%). Rainfall in the monsoon core zone, which includes most of the rain-fed agriculture regions in the country, was above normal at 106% of LPA. Rainfall over the country as a whole was 110%, 93%, 76% and 135% of LPA during June, July, August and September respectively, it added.

IMD said the monsoon would start withdrawal from northwest India from October 6 this year. In 2019, monsoon withdrawal was the most delayed, commencing on October 9. Last year, the monsoon commenced its withdrawal on September 28, delayed compared to the normal date of September 17.

IMD, however, did not forecast as to when monsoon it would withdraw completely from the country this year.

According to IMD’s probabilistic forecast for October, there is likely to be above normal rain over most parts of the country. There is likely to be above normal rain over most parts of northwest India during October to December period, which is usually dry while there is likely to be near normal rain over peninsular India during the last three months of the year when the northeast monsoon brings rain to the region.

M Mohapatra, director-general, IMD, said it is too early to say whether the above-average rain in October and November would affect the standing winter crop in different parts of the country.

IMD’s extended-range forecast indicates that there is likely to be widespread rain over central and western parts of India till October 14. “During the October to December period, we can expect light or scattered rain episodes over northwest India but not very heavy rains. The region is normally dry during October to December period.

Due to approaching La Nina there may be clouding over some areas which may bring down maximum temperatures,” said DS Pai, scientist and head of climate research and services, IMD, Pune.

Currently, cool ENSO neutral conditions prevailing over the equatorial Pacific Ocean and negative IOD conditions over the Indian Ocean. The sea surface temperatures (SSTs) over central and east equatorial Pacific Ocean are showing a cooling tendency and the latest global model forecasts indicate that there is an increased possibility of re-emergence of the La Niña conditions during the next three months.