Southwest Monsoon Resumes Advance, Expected in Mumbai Within 48 Hours

The southwest monsoon has resumed its progress across India after stalling last week and is expected to reach Mumbai within the next 48 hours. The India Meteorological Department (IMD) clarified that showers observed in Mumbai on Monday were pre-monsoon activity, not the official onset.

The national rainfall deficit though remains severe. It stood at 43% as of Monday, June 22. The country received just 60.6 mm of rain, falling short of the normal 106 mm benchmark for this period.

Gradual Progress Expected

Meteorologists attribute the slow advance to missing weather systems.

"The monsoon has seen a slight revival, particularly on the western side. We had forecast the same a few days ago, that it should pick up again around June 22 and 23. However, a low pressure area over the Bay of Bengal is still missing and should only develop towards the end of the month," said OP Sreejith, head of the IMD climate monitoring and prediction group. "We can only expect gradual progress in the coming days till the end of the month, when it should finally pick up intensity," he added.

Mahesh Palawat, vice-president at private forecaster Skymet, told The Hindustan Times that while the revival on the western side is good news, it can only be called a brief revival at this stage. He added that an eastern low-pressure system will likely form only by June 29.

"This delays progress into UP and Delhi. We may expect that only towards the first week of July," Palawat said. Delhi normally sees the monsoon arrive around June 27.

Advance and Deficits

The weather system advanced further on Monday. It moved into parts of the central Arabian Sea, Maharashtra, Telangana, Karnataka, Chhattisgarh, Odisha, Jharkhand, and Bihar. "Conditions are favourable for the southwest monsoon to further advance into remaining parts of central Arabian Sea, some more parts of Maharashtra – including Mumbai, remaining parts of Telangana and Odisha, some more parts of Chhattisgarh, Jharkhand and Bihar during the next 48 hours," the IMD added in its bulletin.

The northern limit of the monsoon passed through Alibag, Pune, Nizamabad, Dantewada, Balangir, Sundargarh, Chatra, Gaya, and Muzaffarpur on Monday.

The monsoon initially entered Maharashtra on June 8, four days after it reached Kerala, but stalled due to El Niño conditions and a lack of localised weather systems. The weather system normally reaches Mumbai around June 11.

Regional shortfalls are steep. Central India is the worst hit with a 67% deficit. East and northeast India are down 40%, the southern peninsula dropped 28%, and northwest India sits 15% below the average.

The IMD projects overall monsoon rainfall at 90% of the long-period average. El Niño conditions are expected to suppress rainfall, particularly in the second half of the season.