The first cyclonic storm of this year’s northeast monsoon is likely to bring extremely heavy rain to one or two places in the delta region and the northern coastal districts of Tamil Nadu on Tuesday and Wednesday.
To be named ‘Nivar’, as suggested by Iran, according to the list prepared by the World Meteorological Organisation’s panel, the weather system, currently a deep depression over southwest Bay of Bengal, is about 360 km east-southeast of Puducherry and 420 km southeast of Chennai.
Also read: Low pressure will bring rain, says IMD
It is likely to intensify into a cyclonic storm during the next 12 hours, and further into a severe cyclonic storm during the subsequent 24 hours. It is very likely to move northwestwards and cross the Tamil Nadu and Puducherry coasts between Karaikal and Mamallapuram around Puducherry as a severe cyclonic storm on Wednesday evening.
Officials of the Meteorological Department said the rain spells over the State would last three days, till November 26.
The Department has issued a red alert, indicating that the State authorities should take action as extremely heavy rain of over 24.4 cm is possible in one or two places in some districts, including Thanjavur, Nagapattinam and Tiruvarur, on Tuesday.
More districts, including Villupuram, Tiruvannamalai, Cuddalore and Perambalur, are likely to get extremely heavy rain in isolated places on November 25.
20 kmph speed
S. Balachandran, Deputy Director General of Meteorology, Chennai, said the potential cyclone was moving at an average speed of 20 kmph. “Squally weather with wind speeds of 55-65 kmph may prevail in the north coastal areas on Tuesday and Wednesday. Heavy to very heavy rain (up to 24 cm) may occur in isolated places of north coastal areas, including Vellore, Tiruvallur, Kancheepuram and Krishnagiri, on both the days. Chennai, too, will experience very heavy rain in some areas,” he said.
“We are monitoring the dynamic weather system and tracking the landfall. We expect the system to reduce the overall deficit in the State’s seasonal rainfall, which stands at 25%,” he added.
Senior meteorologist Y.E.A. Raj noted that in all probability, it may be a rain-filled storm, and may not have time to intensify further as its travel over the ocean area is less.
“Nearly 13 weather disturbances have crossed the Karaikal-Mamallapuram belt during November and December, going by the records from 1971. A depression in 1993 and a cyclonic storm in 1994 originated from the same location as the present weather system,” he said.
The Meteorological Department warned of a storm surge of 2 m near the landfall area, which may cause flooding in low-level areas.