Coastal T.N. to experience intense rainfall from November 26 to 30

The prevailing weather system concentrated into a depression on November 25. The depression is likely to move northwestwards and gather strength as a deep depression by November 26

An intensifying weather system over the Bay of Bengal and the adjoining Equatorial Indian Ocean is expected to bring intense rainfall, which can be extremely heavy in some pockets, to the coastal region of Tamil Nadu over the next five days.

The Regional Meteorological Centre, Chennai, has issued a red weather alert indicating the possibility of extremely heavy rainfall of over 24.4 cm in one or two places in the Mayiladuthurai, Nagapattinam, and Tiruvarur, and Karaikal areas on November 26 and the Cuddalore, Mayiladuthurai, and Karaikal areas on November 27. The delta districts may experience another round of heavy rainfall this week owing to an impending deep depression.

The depression over southwest Bay of Bengal and adjoining East Equatorial Indian Ocean now lies over the same region, about 450 km south-southeast of Trincomalee, 740 km south-southeast of Nagapattinam, 860 km south-southeast of Puducherry and 940 km south-southeast of Chennai.

It is likely to move nearly northwestward and intensify into a deep depression by Tuesday morning. It is further likely to move north-northwestward towards Sri Lanka - Tamil Nadu coasts subsequent during the two days.

The RMC has issued orange and yellow weather alerts, indicating varying intensity of heavy rainfall, for isolated places in various other delta districts and coastal districts between November 26 and November 30. On Tuesday, rainfall of very heavy intensity may lash six districts, including Thanjavur, Pudukottai, and Cuddalore, and it may be heavy over five districts, including Ramanathapuram and Chengalpattu.

Rains in Chennai

Chennai and its neighbouring districts, which have been waiting for their share of the monsoon rainfall, may also be covered in this vigorous rainfall activity. The RMC has predicted heavy rainfall over isolated places in Chennai and its surrounding districts from November 27 to November 29. Heavy rainfall may continue over Tiruvallur, Ranipet, and Kancheepuram districts on Saturday (November 30, 2024).

S. Balachandran, Additional Director General of Meteorology, RMC Chennai, said the weather system is being monitored for its further growth as a cyclone and its crossing point. The depression is still in the equatorial ocean and needs to move further.

Multiple factors like Madden Julian Oscillation, westerly trough, and Rossby waves influenced the trajectory of the weather system and rainfall intensity. Moreover, the system’s interaction with the land as it moves close to the Sri Lanka coast would also influence the rainfall pattern. The department is tracking the system for its movement, he said.

Tamil Nadu has so far received an overall rainfall of 32.6 cm against its average of 33 cm since October 1, and this is considered normal rainfall.

On the prospects of rainfall over Chennai, Mr. Balachandran said this weather system would bring substantial rainfall over the coastal districts, and the city too has chances of receiving heavy rainfall.

The RMC has also predicted squally weather to prevail over the Tamil Nadu coast, Comorin area, and Gulf of Mannar this week, and advised fishermen at deep sea to return to the coast immediately.

Published - November 25, 2024 05:22 pm IST