Third Low-Pressure System Likely Over Bay of Bengal on Nov 13

A third low-pressure system is likely to develop over the Bay of Bengal on November 13, while its possible impact on Tamil Nadu remains uncertain.

According to the weather forecast, rain is expected to continue on November 12 in delta and southern districts, including Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai, Pudukkottai, Sivaganga, Madurai, Virudhunagar, Theni, Tenkasi and Kanyakumari. Rain activity is likely to weaken on November 13, followed by showers in coastal and northern districts, including Chennai, Tiruvallur and Chengalpattu, on November 14. Heavy rainfall is forecast in parts of the Cauvery delta on November 15 and in the Nilgiris and Coimbatore on November 16.

Meanwhile, researchers from IIT Madras and Gauhati University have developed a new scientific method to identify large-scale monsoon systems by distinguishing widespread monsoon activity from isolated local rainfall. Published in the Journal of Climate, the study analysed 84 years of rainfall data. It estimates that large-scale monsoon onset generally occurs around May 15 in Northeast India and June 9 over the Indian Peninsula. The research explains how scattered rainfall clusters gradually merge into an interconnected monsoon system.