Tamil Nadu rain alert conditions are set to continue through October 20, with Chengalpattu under an orange alert for very heavy rainfall and nine districts warned of similar intense rain on October 20, according to a report issued by the Chennai Meteorological Centre.
The warning comes as an atmospheric circulation persists over parts of Tamil Nadu. Another circulation is present over south coastal Andhra Pradesh and adjoining areas, while a low-pressure trough has formed over the Bay of Bengal to its northwest, the Centre said. These weather systems are contributing to ongoing rainfall across the state.
For October 17, Chengalpattu is forecast to receive very heavy rain. The warning is particularly significant for the district because intense rainfall can affect road movement, low-lying areas and local drainage systems, although the report did not provide specific accumulation figures or instructions on closures.
The Centre forecast heavy rain on October 18 across the Nilgiris, Coimbatore, Erode, Krishnagiri, Dharmapuri, Salem, Tiruvannamalai, Kallakurichi, Perambalur, Tiruchirappalli, Ariyalur, Cuddalore, Villupuram, Chengalpattu, Kancheepuram, Tiruvallur and Chennai districts. Puducherry is also included in the forecast.
On October 19, heavy rain is expected in Tiruvallur, Chennai, Kancheepuram, Chengalpattu, Villupuram, Kallakurichi, Cuddalore, Perambalur, Ariyalur, Mayiladuthurai, Tiruvarur, Nagapattinam, Thanjavur, Pudukkottai, Sivaganga, Ramanathapuram, Thoothukudi, Tirunelveli and Puducherry.
The warning for October 20 covers nine districts: the Nilgiris, Coimbatore, Tiruppur, Dindigul, Theni, Virudhunagar, Tenkasi, Tirunelveli and Kanniyakumari. These districts are forecast to receive very heavy rain.
The sequence places Chennai and several districts in its metropolitan and surrounding region within the rainfall forecast on both October 18 and 19. Chengalpattu, Kancheepuram and Tiruvallur are included on both days, making the regional warning relevant to commuters, public transport operations, construction activity and municipal drainage management.
The report did not specify changes to transport services, school operations, work schedules or emergency measures. It also did not provide a district-wise rainfall amount or identify areas expected to experience waterlogging. Further operational advisories, if issued by district administrations or civic authorities, would determine local responses as the weather system develops.
