Cyclone Nisarga on course, Maha and Guj on alert

Thousands evacuated along the Konkan, Saurashtra, south Gujarat coast; rescue teams get Covid kits; shelters readied as landfall is expected near Alibaug between 12pm and 3pm

NEWDELHI/MUMBAI: A deep depression over east-central Arabian Sea, which intensified into cyclone Nisarga on Tuesday noon is expected to make landfall as a severe cyclonic storm with a wind speed of 100 to 110 kmph gusting to 120 kmph near Alibaug in Raigad district on June 3, the India Metereological Department (IMD) said on Tuesday. Located 94 km (by road) from Mumbai or 16 km or 9 nautical miles south of Mumbai over the sea, Alibaug is a popular seaside resort town for Mumbai’s elite and home to a large fisherfolk community.

It started as a warning on Sunday for mid-week heavy rains in Mumbai and by Monday, rapidly developed into a red alert for several coastal districts as the deep depression progressed over the Arabian Sea. As of Tuesday evening, cyclone Nisarga was 280 km west northwest of Panjim, Goa, 350 km south-southwest of Mumbai, 300 km south-southwest of Alibaug, and 560 km south southwest of Surat, Gujarat. The IMD said that the cyclone was likely to cross north Maharashtra and the south Gujarat coast on Wednesday afternoon.

“Landfall over Alibaug is expected around noon Wednesday, and the impact will continue till around 3 pm across all four districts,” said Sunitha Devi, in-charge of cyclones at IMD.

The western coastline from Konkan’s Sindhudurg and Ratnagiri to Saurashtra’s Bhavnaroxy gar and other districts of Gujarat including Surat and Bharuch have received wind warnings ranging from 55-65 kmph (gusting to 75kmph) and increasing to gusting speeds of 115-120kmph in four Maharashtra districts of Palghar, Mumbai, Thane and Raigad. “Extensive damage can be expected in Mumbai also,” M Mohapatra, director general, IMD, said.

Additional storm surge warnings — shoreward movement of water above astronomical tide height under the action of wind stress — have also been issued for Raigad, Thane, Greater Mumbai and Ratnagiri. Storm surges indicate the extent of inundation to expect. A storm surge of 0.5m to 1.3m over coastal Alibaug may result in flooding up to 1.4km of low-lying area.

Mumbai and Thane, already beleaguered by a daily caseload of Covid-19 infections — the capital city breached the 40,000 mark at the start of the week — are in the cyclonic path, leading to concern over whether the city health care infrastructure would cope.

Mathew Koll, senior scientist, Indian Institute of Tropical Meteorology Pune, said that if landfall happened over Raigad, maximum rainfall should be expected over areas to its north, where Mumbai is. “If this happens during high tide, then flooding will be a major concern for a city that is already clogged.”

“The last severe cyclonic storm to hit close to Mumbai was in 1961. The important thing is to take all precautions possible, which state governments are trying,” said Mohapatra.

But experts warned that devastation can be extensive as today’s Mumbai is very different from the Bombay of 1960’s and has lost most of its floodplains and rivulets and is now counted as among the densest cities in the world. “When heavy rains lash over a city like Mumbai which has lost its flood plains and defences, the flooding gets prolonged there too,”said Koll.

IMD officials said pre-monsoon cyclones like Nisarga were not a rare event, citing the example of very severe cyclone Vayu in June 2019, which was supposed to have made landfall over the Gujarat coastline, but ended up as a low pressure system. “We are observing the increase in premonsoon cyclones in Arabian Sea. While we should not draw a trend until observing such weather systems for at least a few years, we are assessing whether these systems are intensifying faster than before [which could be] due to numerous factors including rising ocean temperatures,” said Sunitha Devi.

“Some of the weakest cyclones at sea are being strengthened due to global warming and climate change impacts,” Anjal Prakash, author of an Intergovernmental Panel on Climate Change report, said.

The name, Nisarga proposed by Bangladesh, means ‘nature’. It comes in the wake of cyclone Amphan that devastated the lives of over a million people and left 86 dead when it made landfall on May 21 at the Sunderbans, in West Bengal.

“Our weather models are showing the landfall north of Mumbai with crucial period of extremely heavy rain and gale winds expected from Tuesday evening to Wednesday afternoon,” said Mahesh Palawat, vice president (meteorology and climate change).

The last severe cyclonic storm to hit close to Mumbai was in 1961... The important thing is to take all precautions possible, which state governments are trying.

M MOHAPATRA, director general, IMD