NEW DELHI, 13 May: The southwest monsoon advanced into parts of the south Bay of Bengal, south Andaman Sea, Nicobar Islands, and some areas of the north Andaman Sea on Tuesday, the India Meteorological Department (IMD) said.
The weather department said that moderate to heavy rainfall lashed Nicobar Islands in the past two days.
The strength and depth of westerly winds over the south Bay of Bengal, Nicobar Islands and Andaman Sea increased in this period, with wind speeds exceeding 20 knots at 1.5 km above sea level and extending up to 4.5 km in some areas.
The outgoing longwave radiation (OLR), an indicator of cloudiness, also decreased over the region. These conditions meet the criteria for the monsoon’s onset over the region, it said.
The weather office said conditions are favourable for the monsoon to advance further into more parts of the south Arabian Sea, Maldives and Comorin area; more areas of the south Bay of Bengal; the entire Andaman and Nicobar Islands; remaining parts of the Andaman Sea; and parts of the central Bay of Bengal over the next three to four days.
The primary rain bearing system is likely to reach Kerala on 27 May, earlier than the usual date of 1 June.
If the monsoon arrives in Kerala as expected, it will be the earliest onset over the Indian mainland since 2009, when it began on 23 May, according to IMD data.
Normally, the southwest monsoon makes its onset over Kerala by 1 June and covers the entire country by 8 July. It starts retreating from northwest India around 17 September and withdraws completely by 15 October.
The IMD had in April forecast above-normal cumulative rainfall in the 2025 monsoon season, ruling out the possibility of El Niño conditions, which are associated with below-normal rainfall in the Indian subcontinent.
The monsoon is crucial for India’s agriculture sector, which supports the livelihood of about 42 percent of the population and contributes about 18 percent to the country’s GDP. It is also vital for replenishing reservoirs critical for drinking water and power generation across the country. (PTI)
