The Regional Meteorological Centre (RMC) in Chennai has issued an orange alert for heavy to very heavy rainfall across multiple districts of Tamil Nadu, including Chennai, as a low-pressure system is expected to form over the southeast Bay of Bengal between October 21 and 24.
According to the RMC, a low-pressure area currently persists over the southeast Arabian Sea, while an upper-air circulation prevails over the southern Andaman Sea and the adjoining southeast Bay of Bengal.
This system is likely to intensify into a low-pressure area within the next 24 hours and move west-northwestward, strengthening further over the southwest and west-central Bay of Bengal in the following 48 hours.
As a result, the weather office has issued an orange alert for seven districts — Ramanathapuram, Pudukkottai, Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, and Cuddalore — warning of extremely heavy rain on Monday (October 21).
Additionally, heavy rainfall is expected in Kanniyakumari, Tirunelveli, Thoothukudi, Villupuram, Chengalpattu, Tiruvallur, Chennai, Kancheepuram, Ariyalur, Perambalur, and Sivaganga districts during the same period.
For October 22, the RMC has extended the orange alert to Tiruvallur, Chennai, Chengalpattu, Kancheepuram, Villupuram, Ranipet, and Tiruvannamalai districts, while predicting heavy rain in Krishnagiri, Dharmapuri, Villupuram, Tiruvannamalai, and Tirupattur districts. The forecast for October 23 warns of very heavy rainfall in Tiruvallur, Chennai, Chengalpattu, Kancheepuram, Ranipet, and Vellore, while Krishnagiri, Dharmapuri, Villupuram, Tiruvannamalai, and Tirupattur may experience heavy showers.
By October 24, districts including Tirupattur, Vellore, Krishnagiri, Chennai, Tiruvallur, Kancheepuram, Ranipet, Tiruvannamalai, Erode, Nilgiris, Coimbatore, Dharmapuri, and Krishnagiri are expected to witness intense rainfall.
In Chennai, the sky will remain generally cloudy with the likelihood of moderate to heavy rain accompanied by thunderstorms in several parts of the city, the RMC said.
Officials have urged residents in low-lying areas to remain alert and avoid waterlogged zones, as continuous rain may cause flooding in parts of northern Tamil Nadu and the Delta region over the coming days.
