CHENNAI: The deep depression over the Southwest Bay of Bengal remained stationary about 100 km east-northeast of Trincomalee. The depression, which lay about 300 km southeast of Nagapattinam, 400 km southeast of Puducherry, and 480 km southeast of Chennai, may become a cyclonic storm tonight or early tomorrow morning but would weaken as a deep depression while crossing the coast between Karaikal and Mahabalipuram on November 30, S Balachandran, Director, Regional Meteorological Centre, said. The rainfall activity will start over Chennai and neighboring districts from Friday morning, gradually increase and peak on Saturday.
“There are many factors responsible for the cyclone to become weak. The wind speed is higher in the shear region but lower near the core. There is a marginal chance for the deep depression to develop into a cyclone,” Balachandran said. The weakened system would not allow the formation of clouds and reduce the chances of cyclone formation, he said.
The meteorological centre has issued a red alert for several coastal districts on November 29 and 30. The Met office has issued a red alert for Chengalpattu, Villupuram, Cuddalore, Mayiladuthurai, Tiruvarur, Nagapattinam, Puducherry and Karaikal areas on Friday as scattered heavy to very heavy rain with extremely heavy rain is forecasted. A red alert has been issued for Saturday for Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Villupuram, Kallakurichi, Cuddalore districts and Puducherry.
Heavy rain likely, but not strong winds: Ex-IMD chief
Villupuram and Cuddalore have declared a holiday for schools and colleges on Friday while schools and colleges in Puducherry will remain closed on Friday and Saturday. Former IMD chief KH Ramesh told TNIE there will be heavy rains, but the saving grace is that the system will weaken and won’t bring with it strong winds to cause any damage to property. “Also, there won’t be noticeable storm surges which would help Chennai rivers to drain the road run-off faster,” he said.
Ramesh said Sri Lanka, in the last three days, got over 600mm of rainfall but Tamil Nadu might not see such extreme rains as dry northwesteries will play its part. “There is a possibility of big rains falling over the sea, but still areas between Puducherry and Chennai would see rainfall in the range of 15 cm to 20 cm in a day. It will be a see-saw battle between the approaching weather system and atmospheric conditions on the land. Most of the models are showing landfall on the evening of November 30.”
The state did not witness any significant rainfall activity on Thursday.