CHENNAI: A well-marked low-pressure area over the Bay of Bengal and the Indian Ocean intensified into a depression on Monday. The Regional Meteorological Centre (RMC) has issued a red alert for delta districts of Mayiladuthurai, Nagapattinam and Tiruvarur, and Karaikal in Puducherry on Tuesday with extremely heavy rainfall (over 20.4 cm) forecast, and for Cuddalore, Mayiladuthurai, and Karaikal districts on Wednesday.
An orange alert has been issued for Villupuram, Cuddalore, Ariyalur, Thanjavur, Pudukkottai and Sivaganga districts and Puducherry on Tuesday, forecasting heavy to very heavy rainfall (11.56 cm to 20.44 cm) at isolated places. Ramanathapuram, Tiruchy, Perambalur, Kallakurichi and Chengalpattu districts are expected to receive heavy rain at isolated places (6.45 cm to 11.5 cm), for which a yellow alert has been issued.
On Wednesday, an orange alert has been issued for Ariyalur, Tiruvarur, Nagapattinam, Thanjavur, Pudukkottai and Villupuram districts and Puducherry, with heavy rain likely in Ramanathapuram, Sivaganga, Tiruchy, Perambalur, Kallakurichi, Chengapattu, Chennai and Kancheepuram districts.
According to the RMC, while heavy to very heavy rainfall at isolated places is likely in Chengalpattu, Kancheepuram and Villupuram districts on Thursday, heavy rainfall is expected in Chennai, Tiruvallur, Ranipet, Tiruvannamalai, Kallakurichi and Cuddalore districts and Puducherrry.
As of 5 pm on Monday, the depression is centred 530 km southeast of Trincomalee in Sri Lanka and 810 km southeast of Nagapattinam.
Weather bloggers unsure about Chennai rains
The depression is likely to move northwest and intensify into a deep depression over the next 24 hours. In the two subsequent days, the depression is likely to move north-northwest towards the coasts of Sri Lanka and Tamil Nadu.
Meanwhile, weather bloggers are uncertain if the weather system would bring very heavy rainfall for Chennai and its surrounding districts, as the system’s movement could be ascertained only on Tuesday morning.