CHENNAI: Chennai and parts of Tamil Nadu are bracing for heavy to very heavy rainfall as a cyclonic system is developing over the Southwest Bay of Bengal.
According to the regional meteorological centre here, the system, currently classified as a deep depression, is expected to intensify into a cyclonic storm within the next 12 hours, bringing widespread rainfall and strong gusts to the region.
As of Wednesday afternoon, the system was positioned approximately 120 km east-southeast of Trincomalee, Sri Lanka, and about 550 km south-southeast of Chennai.
Moving north-northwest at a speed of 13 kmph, the system is projected to approach the Tamil Nadu coast while skirting the Sri Lankan coastline over the next two days. It is likely to cross the coast between Cuddalore and Chennai around November 30.
The IMD has issued a severe weather warning for Tamil Nadu, Pondicherry, and Karaikal, predicting heavy rainfall across multiple districts.
On November 28, orange alert was issued for Kancheepuram, Chengelpattu, Villupuram and Cuddalore district and Pondicherry as heavy to very heavy rainfall is forecasted.
On November 29-30, the orange alert was issued for Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Ranipet districts. The rain is forecasted to persist in Chennai and surrounding areas through December 1, accompanied by moderate showers and intermittent thunderstorms.
“Chennai will get good rains on November 29-30, but those rains will not be threatening. It may be in the range of 150 mm,” said Mahesh Palawat, Vice President (Meteorology and Climate Change) at Skymet to TNIE. He added that the system is likely to weaken as it approaches the coast due to atmospheric dynamics not being conducive for further intensification.
Strong winds are anticipated along the coastal areas, with speeds ranging from 40-50 kmph on November 27, increasing to 55-65 kmph and gusting up to 75 kmph by November 29-30.
The IMD has advised fishermen to avoid venturing into the sea due to rough conditions, and residents are urged to stay indoors and avoid waterlogged areas.
Former IMD Chief K.H. Ramesh also said there is a possibility for the system to weaken as it nears the coast. “The reason is dry air flowing from the north and northwest region may alter the structure and lifecycle of the storm. If that happens, it will not allow the system to intensify. However, the simulations are showing rain bands will reach Chennai and further inland,” he explained.
Ramesh said that the situation would become clearer by Thursday as the system evolves. “We will get a clear picture on Thursday. This is just a possibility. We have to wait and see how things pan out in the next 24 hours,” he added.
Experts say there are several instances in the recent past, where even a low pressure area or a depression has delivered extreme rains. This is a slow moving system and can spring a surprise.
In the 24 hours ending at 8:30 am on Wednesday, Nagapattinam recorded the highest rainfall at 19 cm and several other stations in Cuddalore, Mayiladuthurai, Chennai and its neighboring districts reported over 10 cm.
Disaster management teams are on alert, and emergency services are prepared to handle potential disruptions due to flooding and strong winds.
