Heavy rainfall over south Tamil Nadu and delta districts is set to continue till November 25.
A low pressure area brewing over the Bay of Bengal, which is likely to gain strength next week, will be a key factor in shaping the State’s November rainfall.
The Regional Meteorological Centre (RMC) has forecast that a low pressure area is likely to form over Southeast Bay of Bengal on Saturday. It may concentrate into a depression over central parts of south Bay of Bengal by November 24. The weather system is expected to gather further strength by November 26. The RMC is monitoring the prospects of the weather system intensifying into a cyclonic storm.
P. Senthamarai Kannan, Director, Area Cyclone Warning Centre, Chennai, said rainfall in Tamil Nadu would depend on the trajectory of the weather system after it intensifies into a depression. A strong northeast monsoon current influenced the ongoing rain spell in the State, particularly south coastal and delta region, he said.
The RMC has forecast heavy rainfall in 11 districts, including Cuddalore, Thanjavur, Nagapattinam, and Kanniyakumari, for Saturday.
While many places in south Tamil Nadu are likely to receive rainfall of light to moderate intensity, a similar pattern of heavy rain may continue in south coastal and delta districts till November 24.
As of now, only isolated rainfall has been predicted over the State on November 25. Dry, long spells this month have pushed the State’s seasonal rainfall to 28.4 cm, which is 7% lower than the average of 30.5 cm. However, the Meteorological Department considers a deviation — excess or deficit — of up to 19% as normal.
Tiruppur, Chengalpattu, Perambalur, Dindigul, and Chennai are among the districts that have received deficit rainfall since October 1. In its outlook for November, the RMC said that there was a 35%-45% probability for most parts of Tamil Nadu and Puducherry to receive below normal rainfall this month.
On Friday, some districts, including Vellore, Nagapattinam, Chennai and Kanniyakumari, received light rainfall till 6 p.m.
The Meteorological Department has forecast that Chennai may experience one or two spells of light/moderate rainfall on Saturday.
Published – November 22, 2025 12:18 am IST
