The India Meteorological Department (IMD) has indicated the possible formation of a low-pressure area over the southeast Bay of Bengal around November 23, based on the weather update issued at 8:30 AM IST on November 19.
An upper air cyclonic circulation is expected to develop over the South Andaman Sea and nearby regions by November 21. This system is forecasted to move west-northwestwards, leading to the development of a low-pressure area over the southeast Bay of Bengal two days later.
Further intensification is anticipated, with the system likely strengthening into a depression over the southwest Bay of Bengal during the following 48 hours.
The Regional Meteorological Centre (RMC) has forecast heavy rainfall in 10 districts of Tamil Nadu on Tuesday prompting the Nagapattinam District Collector to declare a holiday for all schools in the district.
In Thanjavur, school heads have been given discretion to decide on closures based on local conditions.
Heavy rains are expected in the following districts: Nagapattinam, Thiruvarur, Thanjavur, Mayiladuthurai, Pudukottai, Sivaganga, Thoothukudi, Ramanathapuram, Tirunelveli and Kanyakumari. Additionally, starting November 22, heavy rainfall is expected in Chennai and the northern coastal districts of Tiruvallur, Chengalpattu, and Kancheepuram.
These districts are predicted to receive above-normal rainfall until November 28, while the rest of the state is likely to experience normal to below-normal rainfall during this period.