CHENNAI: The slow moving cyclonic storm Nivar over the warm waters of the Bay of Bengal is turning into a monster. The Indian Meteorological Department (IMD) on Tuesday announced that Nivar will intensify into a very severe cyclonic storm while making landfall late on November 25 evening with wind speeds of 120-130 kmph gusting to 145 kmph.
S Balachandran, deputy director general of meteorology of Regional Meteorological Centre, Chennai, told reporters that the storm was moving at 5 kmph and lay centered over southwest Bay of Bengal about 380 km east-southeast of Pondicherry and 430 km south-southeast of Chennai.
"Nivar will intensify into a severe cyclonic storm by Wednesday morning and into a very severe cyclonic storm in the subsequent 12 hours. It is very likely to cross the Tamil Nadu and Puducherry coasts between Karaikal and Mahabalipuram around Puducherry late on November 25 evening," Balachandran said.
The official said gale wind speed reaching 65-75 kmph gusting to 85 kmph can be experienced from the morning of November 25 and 120-130 kmph gusting to 145 kmph along and off coastal districts of north Tamil Nadu and Puducherry (Nagapattinam, Karaikal, Myladuthurai, Cuddalore, Villupuram and Chengalpet districts; 80-90 gusting to 100 kmph very likely over Tiruvarur, Kanchipuram, Chennai, Tiruvallur districts) during noon to night of November 25.
Experts say the chances of Nivar further intensifying can't be ruled out considering both ocean and atmospheric conditions. "Conditions have been favourable for the development of Cyclone Nivar. The sea surface temperatures in the south Bay of Bengal is 29-30°C. These temperatures are 0.5-1.0°C above normal, which can make a difference. The wind conditions were also favorable as the Madden Julian Oscillation (MJO), associated with enhanced convection and winds, was active in this region," said Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology (IITM).
He also said the more Cyclone Nivar hangs around in the Bay of Bengal, the more energy it draws in. "Basically, if cyclones move very fast, it means the coupling with the ocean is less. If it goes slow, there's more coupling and exchange of energy. There's more warm waters, which potentially means more energy for the cyclone," he said.
Weather blogger Pradeep John said though the landfall is likely to happen near the Puducherry to Marakkanam belt, Chennai would experience gusts in excess of 100 kmph since the storm is moving northwards. "Chennai will also feel the impact," he said.
Chennai receives over 10 cm of rainfall
Chennai on Tuesday was battered with heavy rainfall receiving over 100 mm, which led to waterlogging in many parts of the city, especially southern and central parts.
Nungambakkam weather station has recorded 106.5 mm of rainfall from 8.30 am, while Meenambakkam station near the airport has clocked 78 mm of rainfall.
IMD has issued a red alert in seven districts of Tamil Nadu and Puducherry. Extremely heavy rain is likely to occur at isolated places over Tiruvannamalai, Kallakurichi, Villupuram, Cuddalore, Ariyalur, Perambalur and Mayiladuthurai districts of Tamil Nadu and Pondicherry.
Heavy to very heavy rain is likely to occur at isolated places over Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Ranipet, Vellore, Tirupattur, Krishnagiri, Dharmapuri, Salem, Erode, Namakkal, Trichy, Nagapattinam, Tiruvarur and Thanjavur districts, Balachandran said.
Meanwhile, officials at the Indian National Centre for Ocean Information Services (INCOIS) issued high wave warnings for north and south Tamil Nadu. Chennai, Chengalpet and Pondicherry coasts will experience significant wave height of 3 - 4.9 metres and swell height of 1 - 3 metres from Tuesday to Wednesday midnight.