The India Meteorological Department has forecast an early arrival of the southwest monsoon over the Andaman Sea, with conditions becoming favourable for its onset over parts of the south Bay of Bengal and the Andaman and Nicobar Islands by the weekend.

A low-pressure area currently lying over the southwest Bay of Bengal is expected to intensify further over the next 48 hours, creating the atmospheric conditions necessary for monsoon advancement.

The anticipated arrival comes ahead of the typical 20 May timeline when the monsoon generally reaches the Andaman and Nicobar Islands.

An early onset over the Andaman region is often seen as the first major indicator of the monsoon's overall progress across the country.

IMD Director General M Mohapatra said the department is expected to issue a forecast regarding Kerala's monsoon onset on or around 15 May, with the normal onset date over Kerala being 1 June.

The department launched two advanced weather forecast products on Monday, including India's first artificial intelligence-enabled monsoon advance forecasting model.

The block-level monsoon onset forecast model combines existing numerical weather prediction models with AI to generate probabilistic forecasts of monsoon progression every Wednesday up to four weeks in advance, while the forecasting system currently covers 3,196 blocks across 15 states and one Union Territory.

Despite the early onset, the weather department has forecast below-normal rainfall for the 2026 southwest monsoon season.

The seasonal rainfall over the country as a whole is most likely to be below normal at 92 per cent of the Long Period Average with a model error of ±5 per cent.