Monsoon expected to revive in September: IMD

Monsoon to revive over weekend, bringing rain to central/southern India; Sept likely to witness normal rainfall; El Nino main factor behind deficient Aug rainfall; Indian Ocean Dipole turning positive, countering El Nino; Madden Julian Oscillation/rainfall in tropics turning favourable, aiding monsoon revival.

After deficient rainfall activity resulted in India experiencing the driest August since 1901, the Southwest Monsoon is expected to revive over the weekend bringing rain to central and southern parts of the country, the weather office said on August 31.

Addressing a press conference virtually, India Meteorological Department Director General Mrutyunjay Mohapatra said September was likely to witness normal rainfall in the range of 91-109 per cent of the long period average of 167.9 mm.

However, Mr. Mohapatra said even if the rainfall in September was to remain on the higher side, the June-September seasonal rainfall average is expected to be below normal for the season.

He said the development of El Nino conditions in the equatorial Pacific Ocean was the most important factor behind the deficient rainfall activity in August.

However, the Indian Ocean Dipole — the difference in sea surface temperature of Arabian Sea and the Bay of Bengal — has started turning positive, which could counter the El Nino impact, Mr. Mohapatra said.

He said the Madden Julian Oscillation — the eastward-moving pulse of cloud — and the rainfall in the tropical region too was turning favourable and play a role in the revival of monsoon.