Red alert for north coastal Tamil Nadu, Chennai braces for first threatening spell

CHENNAI: The Regional Meteorological Centre (RMC) in Chennai has issued a red and orange alert for parts of north coastal Tamil Nadu, including Chennai, Chengalpattu, Tiruvallur, Kancheepuram, Villupuram, Cuddalore, and Mayiladuthurai, forecasting isolated spells of extremely heavy rainfall (over 20 cm) on Wednesday as the well-marked low-pressure area in the southwest Bay of Bengal is set to intensify into a depression. The alert will extend into Thursday as the system moves west-northwestwards towards the north Tamil Nadusouth Andhra Pradesh coasts, prompting an orange alert for Chennai, Chengalpattu, Kancheepuram, Tiruvallur, and Ranipet, where very heavy rain (1220 cm) is likely. According to the met office, the associated upper air cyclonic circulation extends up to 7.6 km above mean sea level, creating strong moisture convergence along the coastal and delta districts. The system is expected to intensify further after crossing near the north Tamil Nadu coast and will bring intense spells of rain accompanied by thunder and lightning over the next two days, said P Senthamarai Kannan, from the Regional Meteorological Centre here. Next spells starts in KTCC (Chennai) and as we go into night to morning, it will be the peak time for rains with low nearby ---------------------------- As you can see in the image enclosed, the low will be very close to North TN coast tomorrow morning. Tonight to tomorrow pic.twitter.com/H4eY9MbhkH Tamil Nadu Weatherman (@praddy06) October 21, 2025 Rainfall was reported at most stations across Tamil Nadu in the 24 hours ending 8.30 am Tuesday, with Thangachimadam in Ramanathapuram district recording the highest at 17 cm, followed by Pamban (15 cm), Mandapam (14 cm), and Varattupallam in Erode (13 cm). Along the coast, Velankanni, Annamalai Nagar, Chidambaram, and Medavakkam in Chennai each received 10 cm, while Okkiyam Thoraipakkam and Karaikal recorded 9 cm. Several Chennai zones, including Sholinganallur, Kannagi Nagar, and Injambakkam, saw 8-9 cm, indicating citywide rainfall distribution under an active monsoon regime. In the delta districts, Nagapattinam, Thanjavur, Tiruvarur, and Mayiladuthurai reported 7-9 cm, while Cuddalore and Villupuram recorded around 6-8 cm. Maximum temperatures fell by 2-5 C across most coastal districts due to cloud cover and continuous rain. For the next 48 hours, Chennai will experience heavy to very heavy rain, with maximum temperature around 28 C and minimum near 25 C. Intermittent spells of thunderstorms and lightning are likely. Fishermen have been advised not to venture into the southwest and west-central Bay of Bengal due to strong winds and rough sea conditions. Following heavy rain alerts in several districts, the respective district administrations have declared holidays for educational institutions. Schools and colleges will remain closed in Chengalpattu, Tiruvallur, Cuddalore, Villupuram, Kallakurichi, Thanjavur, Tiruvarur, Puducherry, and Karaikal, while only schools will be closed in Chennai. Chennai Rains: Reservoirs see sharp rise in storage,100 cusecs water being released from Chembarambakkam