Heavy rains batter Tamil Nadu as low pressure deepens over Bay of Bengal

A second weather system, another well-marked low-pressure area over the southeast Arabian Sea, is also poised to become a depression within 24 hours, feeding additional moisture into the region. The dual circulations have kept the northeast monsoon active, the India Meteorological Department (IMD) said.

The RMC has issued orange alerts for Ramanathapuram, Cuddalore, Thanjavur, Nagapattinam, Mayiladuthurai, Villupuram and Puducherry until Wednesday morning. Eleven other districts, including Chennai, Chengalpattu, Tiruvallur and Kancheepuram, are under a yellow alert for heavy rain through the night.

In the 24 hours ending 8.30 am Tuesday, Thangachimadam in Ramanathapuram recorded 17 cm rain — the highest in the state — followed by Pamban (15 cm), Mandapam (14 cm) and Varattupallam in Erode (13 cm). Chennai’s Medavakkam logged 10 cm rain and Sholinganallur 8 cm. The IMD described the northeast monsoon as “active” over Tamil Nadu, and the cities of Puducherry and Karaikal in the Union Territory of Puducherry, with rainfall at most stations.

Heavy inflows into the Vaigai Dam forced the Water Resources Department to issue a third-stage flood alert for Theni, Dindigul, Madurai, Sivagangai and Ramanathapuram districts on Monday. The reservoir stood at 69.13 feet, just shy of its 71-foot capacity, holding 5,605 million cubic feet of water and receiving 4,875 cusecs of inflow. Outflow remained 3,630 cusecs through river and canal channels.

Moderate rainfall continued in Varusanadu and Kottagudi catchments on Tuesday. In Madurai, the river touched both banks, prompting round-the-clock monitoring of causeways and low-lying colonies.

In Chennai, the Water Resources Department increased discharge from the Red Hills reservoir, a key drinking-water source, from 300 to 500 cubic feet per second after a marginal rise in inflow. Water-logging was reported in K K Nagar, Pudupet and parts of Sholinganallur after overnight downpours.

The IMD’s seven-day outlook projects sustained rain across Tamil Nadu, Puducherry and Karaikal. For Tuesday, heavy to very heavy rain with extremely heavy falls is likely in Ramanathapuram, Pudukkottai, Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai, Cuddalore and Villupuram districts and Puducherry and Karaikal.

Heavy-to-very-heavy rain is also forecast in Ariyalur, Perambalur, Kallakurichi, Chengalpattu, Chennai, Tiruvallur, Kancheepuram, Thoothukudi, Tirunelveli and Kanyakumari. Interior districts such as Salem, Tiruchirappalli and Vellore may see isolated heavy showers by mid-week, while western districts — Nilgiris, Erode and Coimbatore — are expected to receive heavy rain by Friday as the system moves inland.

Thunderstorms with lightning are likely over one or two places in the state through October 25.

The IMD observed a significant fall in maximum temperature across Thanjavur, Madurai, Nagapattinam, Tirunelveli, Ramanathapuram and Thoothukudi, where cloud cover and persistent rain have kept afternoons cool. Tiruchirappalli recorded the State’s highest maximum at 33.2°C, while Karur Paramathi registered 20°C, the lowest minimum temperature in the plains.

Disaster-management teams in the coastal belt and delta region have been placed on standby. Authorities have advised fishermen not to venture into the Bay of Bengal and have urged residents in flood-prone localities to remain alert. With both weather systems expected to strengthen, Tamil Nadu may face one of the most vigorous monsoon spells of the season through the end of the week.