IMD forecasts ‘normal’ monsoon this year; El Nino may impact rainfall activities

New Delhi: The Southwest monsoon is likely to remain “normal” for this year, with the rainfall activities expected to 83.5 cm all over the country, as per the India Meteorological Department (IMD) on Tuesday.

The IMD expected normal to below normal rainfall in some areas of north west India and some parts of west central India and some pockets of north east India.

“There is a 67 per cent probability of normal to above-normal rainfall, ” M Mohapatra, Director General of Meteorology, said while releaseing the ‘Long range Forecast for Southwest Monsoon 2023.

“Quantitatively, the southwest monsoon seasonal rainfall between June and September over the country as a whole is likely to be 96 per cent of the Long-Period Average with a model error of plus or minus 5 percent” Director General Mrutyunjay Mohapatra said here.

The LPA of the seasonal rainfall over the country as a whole based on data of 1971-2020 is 87 cm. 

Mrutyunjay Mohapatra said that the El Nino conditions will be developing during the monsoon season, and the impact of El Nino conditions is likely to be felt in the second half of the monsoon season.

He pointed out that all El Nino years have not been bad monsoon years.  Mohapatra also said that out of 15 El Nino years from 1951 to 2022, six years had normal to above normal rainfall.

El Nino involves the unusual warming of waters in the eastern equatorial Pacific, which has a high correlation with warmer summers and weaker monsoon rains in India.

“If at all there is any adverse impact due to the evolving El Nino conditions during the monsoon season, it is likely to be countered by the favourable impact of a positive IOD and the lower snow cover over the northern hemisphere,” Mohapatra said.

“At present, neutral IOD conditions are present over the Indian Ocean and the latest climate model forecast indicates that the positive IOD conditions are likely to develop during the southwest monsoon season.” IMD said.

Mohapatra said a lower snow cover over the northern hemisphere is considered favourable for the subsequent southwest monsoon rainfall over India.

The northern hemisphere snow cover areas during February and March 2023 were observed to be below normal.

Winter and spring snow cover extent over Northern Hemisphere as well as Eurasia has a tendency of general inverse relationship with the subsequent summer monsoon rainfall.