CHENNAI: The deep depression developing over the Southwest Bay of Bengal may intensify into a cyclonic storm within the next 12 hours and bring widespread rainfall to Chennai and parts of Tamil Nadu over the next few days. The cyclone is expected to cross the coast between Cuddalore and Chennai around November 30.
As of Wednesday evening, the weather system was positioned approximately 100km east-southeast of Trincomalee, Sri Lanka, 320km southeast of Nagappattinam, 420km southeast of Puducherry, and 500km south-southeast of Chennai. Moving north-northwest at a speed of 3 kmph, the system is projected to approach the Tamil Nadu coast over the next two days. Puducherry declared a holiday for schools and colleges on Thursday.
In the 24 hours ending 8.30 am on Wednesday, Nagapattinam recorded the highest rainfall at 19 cm and several other stations in Cuddalore, Mayiladuthurai, Chennai and its neighbouring districts reported over 10cm rainfall. The intense rainfall on Wednesday inundated thousands of acres of paddy crop in delta areas
The rain is forecasted to persist in Chennai and surrounding areas through December 1. “Chennai will get good rains on November 29-30, but those rains will not be threatening. It may be in the range of 150mm,” 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.
Experts say slow moving system can spring a surprise
The IMD, meanwhile, has issued a severe weather warning for Tamil Nadu, Puducherry, and Karaikal, predicting heavy rainfall across multiple districts. On November 28, orange alert was issued for Kancheepuram, Chengalpattu, Villupuram and Cuddalore district and Puducherry as heavy to very heavy rainfall is forecasted. On November 29-30, orange alert was issued for Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Ranipet districts.
The intense rainfall on Wednesday inundated thousands of acres of paddy crop across Cauvery delta areas. While 7,500 of 61,000 hectares of samba and thaladi paddy crop in Nagapattinam were flooded with water, over 3,000 hectares in Vedaranyam block and 3,000 hectares in Thalaignayiru block in the district were completely submerged in water, triggering fears of huge damage to the crop. In Mayiladuthurai, around 3,000 hectares in blocks such as Sembanarkoil and Kollidam were affected, officials said. Also, huge acreage of salt pans in Nagapattinam (Vedaranyam) and Villupuram (Marakkanman) districts came under water.
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 said there is a possibility for the system to weaken as it nears the coast.
“The reason is that the 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 said.
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, they said. Disaster management teams are on alert, and emergency services are prepared to handle potential disruptions due to flooding and strong winds. The Indian Coast Guard has stationed disaster relief teams at strategic locations including Chennai, Puducherry, Karaikal, and Tuticorin.
