A weather system over the Bay of Bengal is bringing scattered rain to Tamil Nadu’s coastal regions until Monday. The Regional Meteorological Centre (RMC) issued a yellow alert for some northern districts on Sunday due to possible heavy rainfall. This unusual January weather system caused a break in the dry phase, extending the Northeast Monsoon. On Sunday, heavy rain may fall in isolated areas of Chennai, Chengalpattu, Kancheepuram, Cuddalore, and Villupuram districts. Earlier, heavy rainfall warnings were revised and withdrawn for some places like Tiruvallur due to changes in the system’s movement. B. Amudha, Head (Additional in-charge) at RMC, said the depression over the southwest Bay of Bengal crossed northeast Sri Lanka close to Mullaittivu on Saturday afternoon. The system is expected to weaken into a low pressure area but will still cause wind convergence and rainfall along the coast. "As the northeasterly winds converge towards the centre of the circulation, the wind direction is likely to change to Westerlies," Ms. Amudha explained. On Saturday, coastal places like Chennai saw cool weather with light rain caused by moist winds from the Bay of Bengal. This wet spell should continue till January 16, but rain is likely to reduce from Tuesday. Regarding the heavy rainfall warnings, Ms. Amudha said, "We cannot rule out the possibility of intense downpour in coastal areas whenever there is a system in Bay of Bengal. Early warnings are provided to carry out precautionary measures in multiple sectors. On some occasions, we may not receive rainfall as expected owing to complex weather dynamics." The RMC also predicted cool weather with minimum temperatures expected to stay normal or fall below average across Tamil Nadu, Puducherry, and Karaikal till Monday.