CHENNAI: The deep depression over the Southwest Bay of Bengal has remained stationary, positioned approximately 100 km east-northeast of Trincomalee. Despite its current status, the system—situated 300 km southeast of Nagapattinam, 400 km southeast of Puducherry, and 480 km southeast of Chennai—has the potential to develop into a cyclonic storm later tonight or early tomorrow. However, experts predict it may weaken into a deep depression upon crossing the coast between Karaikal and Mahabalipuram on November 30, according to S. Balachandran, Director, Regional Meteorological Centre.
Rainfall to Intensify
The weather system is expected to bring increasing rainfall activity across Chennai and neighboring districts beginning Friday morning, with the heaviest downpours anticipated on Saturday.
“Several factors are contributing to the system’s weakening,” Balachandran explained. “High wind shear near the core and other atmospheric conditions are reducing the likelihood of the system intensifying into a full-fledged cyclone.” The weakening system is less conducive to cloud formation, further diminishing the chance of a severe storm.
Red Alert for Coastal Districts
The Regional Meteorological Centre has issued a red alert for several districts on November 29 and 30, anticipating heavy to extremely heavy rainfall. Key areas under alert include:
- November 29: Chengalpattu, Villupuram, Cuddalore, Mayiladuthurai, Tiruvarur, Nagapattinam, Puducherry, and Karaikal.
- November 30: Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Villupuram, Kallakurichi, Cuddalore, and Puducherry.
Schools and Colleges Closed
In response to the forecast, schools and colleges in Villupuram and Cuddalore will remain closed on Friday. Puducherry has announced closures for both Friday and Saturday.
Expert Insights: Heavy Rains, Minimal Winds
Former IMD chief K.H. Ramesh emphasized that while heavy rains are expected, the weakened system is unlikely to bring strong winds or significant storm surges. “This is good news as it reduces the risk of property damage and aids in quicker drainage of rainwater in urban areas like Chennai,” he said.
Tamil Nadu is expected to avoid the extreme rainfall seen in Sri Lanka, which recorded over 600mm in three days. “Rainfall between Puducherry and Chennai may range from 15 to 20 cm per day, but it is unlikely to reach catastrophic levels,” Ramesh added. He noted that the system’s interaction with atmospheric conditions on land would ultimately determine the severity of the rainfall.
Forecast for November 30
Most models predict landfall on the evening of November 30, with rainfall intensifying across coastal districts. Residents are advised to stay alert, follow updates from the meteorological department, and take necessary precautions to ensure safety.
