Depression moves 'slow & steady'; may batter north Tamil Nadu on November 29

CHENNAI: Though the weather department issued an orange alert for Chennai along with a few neighbouring districts, the state capital witnessed almost a dry day on Tuesday.

However, as per the forecast on Wednesday, the northeast monsoon’s first cyclone is likely to form over the Bay of Bengal by Wednesday night or Thursday.

The Regional Meteorological Centre (RMC) has given orange and yellow warnings for coastal districts of Tamil Nadu for the next three days. The State may witness winds beyond the normal speed due to the system in the Bay.

The deep depression over southwest Bay of Bengal was moving north-northwestwards with a speed of 13 kmph on Wednesday. It was lying around 120 km east southeast of Trincomalee, 370 km southeast of Nagapattinam, 470 km southeast of Puducherry and 550 km south-southeast of Chennai during the day.

Weather department said that the system was expected to move north-northwestwards and intensify further into a cyclonic storm by Wednesday night or Thursday. Thereafter, it would continue to move north-northwestwards towards Tamil Nadu coast.

Heavy to very heavy rain is likely to occur at isolated places in Kancheepuram, Chengalpattu, Villupuram and Cuddalore districts. Heavy rain is predicted over Chennai, Tiruvallur, Ranipet, Tiruvannamalai, Kallakurichi, Perambalur, Ariyalur, Pudukkottai, Thanjavur, Tiruvarur, Nagapattinam and Mayiladuthurai districts on Thursday.

For November 29 and 30, an orange alert has been issued to Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Ranipet districts. As many as four districts - Vellore, Tiruvannamalai, Villupuram, Cuddalore districts were likely to experience heavy rain and yellow warning was issued to these regions.

While the cyclone is expected to make landfall on Saturday, the intensity of the downpour is expected to subside gradually. Even after the landfall, the cyclone would cause rains in Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Ranipet districts on December 1 and 2.

As per extended range predictions by dynamical models, near normal to slightly above normal rainfall is very likely over north Tamil Nadu. Near normal to slightly below normal rainfall is likely over south Tamil Nadu.

The RMC has issued a wind warning with strong winds speed reaching 45 kmph to 55 kmph gusting to 65 kmph is likely over north coastal districts of Tamil Nadu, adjoining Rayalaseema, south coastal Andhra Pradesh from November 28 to 30.

In addition, Tamil Nadu weatherman Pradeep John stated that the depression/cyclone may cross the coast between Parangipettai, Cuddalore and Chennai mostly on November 30. Since it is crossing south of Chennai, it would be ideal for Chennai’s catchments.