Fresh weather systems to keep Tamil Nadu wet as heavy downpours continue across districts

UPDATE - follow-up to Northeast monsoon gathers momentum in Tamil Nadu; unleashes another round of downpours over Chennai: Fresh weather systems forming over the Bay of Bengal will sustain heavy wet weather across Tamil Nadu until October 27, 2026. A low-pressure area developed over the southwest Bay of Bengal near the State coast during the early hours of Wednesday.

Rainfall Spread

Nighttime downpours struck Chennai and nearby areas, led by MGR Nagar with 15 cm of precipitation and Vadapalani with 14 cm within a day. This deluge boosted storage levels in key drinking water reservoirs. Seventeen southern, delta, and Western Ghats districts including the Nilgiris, Tenkasi, Nagapattinam, and Madurai face forecasts of very heavy precipitation up to 20 cm, while nine other districts such as Erode, Namakkal, and Cuddalore expect heavy showers. Chennai will see a temporary easing of showers before rain picks up again around October 25.

River Alerts

The Central Water Commission issued warnings about rising water levels in rivers like the Vaigai, Tamirabharani, Bhavani, Noyyal, Aliyar, and Moyar across Coimbatore and Theni districts until Friday. Above-normal flood conditions are likely along the Kodaiyar and Paralayar rivers in Kanniyakumari and Tenkasi districts, alongside increased inflows into major reservoirs like Manimuthar and Pechiparai.

Official Outlook

V.R. Durai, head of the Regional Weather Forecasting Centre at the Regional Meteorological Centre, stated that another system could form over the Bay on October 23. While it might turn into a depression moving northwest, weather models suggest it may bypass major impact on the State since October systems often shift toward Andhra Pradesh. Regarding the prior weekend red alert downgrade, he explained that such warnings ensure administrative readiness, and noted that the Greater Chennai Corporation technical team has been asked to check rainfall data networks for errors.

Context

Monsoon weather systems in the Bay of Bengal frequently bring heavy precipitation to coastal and southern Indian states during the autumn months. Authorities track these atmospheric formations closely to manage reservoir levels and issue timely warnings for flood-prone regions.