Cyclone Amphan is poised to slam into West Bengal and Odisha on Wednesday afternoon, packing winds gusting to a speed of 185 kmph, bringing with it torrential rainfall, threatening to inundate low-lying areas of human habitation and cause extensive damage to crops and public property at a time when the nation has its hands full with the coronavirus disease (Covid-19) pandemic.
According to the India Meteorological Department (IMD), Amphan is expected to make landfall between Digha in West Bengal and Hatiya Island in Bangladesh, close to the Sundarbans and around Sagar Island, as a very severe cyclonic storm, bordering on an extremely severe cyclonic storm.
On Tuesday afternoon, the storm was packing wind speeds of 200 to 210 kmph, gusting to 240 kmph. Its intensity had reduced marginally, bordering a super cyclone and an extremely severe cyclonic storm. According to IMD’s glossary, an extremely severe cyclonic storm carries wind speed of between 167 kmph and 221 kmph; a storm is classified as a super cyclone when wind speeds exceed 222 kmph.
National Disaster Response Force (NDRF) director general SN Pradhan said people from low-lying areas were being evacuated.
“The biggest challenge is that we are facing two disasters together—Covid-19 and cyclone. We are also creating awareness about Covid-19 while creating awareness about Amphan and evacuating people,” Pradhan said.
He cited one example what it means to confront two such challenges simultaneously. If a cyclone shelter has a capacity of 1,000, because of social distancing norms and the need to maintain adequate sanitation to curb the spread of Covid-19, only 400 to 500 people can be sheltered there, said Pradhan.
Amphan had been billed as the first super cyclone in the Bay of Bengal since a 1999 storm devastated Odisha, killing around 9,000 people.
“After the 1999 super cyclone, this is the most intense…. Though its wind speed will reduce to 155 to 165 kmph, gusting to 185 kmph, we can expect extensive damage and devastation in South and North 24 Parganas and East Medinipur,” IMD director general M Mohapatra said at a media briefing on Tuesday.
The storm surge is expected to be 4 to 6 metres above the astronomical tide in parts of West Bengal, flooding low lying areas in the three districts when it makes landfall. Wind speeds in Kolkata, Hooghly and Howrah are likely to range between 110 kmph and 120 kmph, gusting to 130 kmph.
Gale-force winds of 75 to 85 kmph, gusting to 95 kmph, are likely to lash the north Odisha coast, including Jagatsignghpur, Bhadrak, Balasore, Kendrapara and other areas.
Meteorologists and climate scientists said that on Monday evening the intensity of Amphan was 145 knots, or 270 kmph. The wind speed passed the 1999 super cyclone velocity of 260 kmph, tweeted meteorologist Eric Holthous, based on data from theUS-based Joint Typhoon Warning Center.
Bay of Bengal recorded sea surface temperature of 32 to 34 degree Celsius prior to the formation of cyclone Amphan, Roxy Mathew Koll, climate scientist at the Indian Institute of Tropical Meteorology, said.
“We have never seen such high values until now. Tropical cyclones draw their energy from the ocean surface and these temperatures can supercharge a cyclone, leading to rapid intensification. Cyclone Amphan intensified from a category 1 to a category 5 cyclone in only 18 hours, it evolved into the strongest cyclone ever recoded in Bay of Bengal,” Koll wrote in a social media post on Twitter, sharing sea surface temperature data from the buoys of the National Institute of Ocean Technology.
Sunita Devi, cyclone scientist at IMD, said the wind speed was 130 knots, or about 240 kmph. “Yes, ocean surface temperatures were high. The sea surface temperature was in the range of 30 to 31° Celsius on Monday, as compared to an expected temperature of 28° Celsius over the region,” Devi said.
“On Tuesday, the maximum temperature is around 30° C. The cyclone is still bordering a super cyclone. Its intensity hasn’t reduced much. We are expecting it to make landfall as a very severe cyclonic storm, again bordering an extremely severe cyclonic storm,” Devi added.
Amphan was a massive cyclone 700 km in extent and 15 km in height when it was rotating around its centre in the central parts of Bay of Bengal on Monday, Mohapatra had said, adding that its very rapid intensification was unusual.
The cyclone is expected to cause heavy to extremely heavy rainfall over Gangetic West Bengal and heavy to very heavy rainfall over north coastal Odisha. It will also cause heavy to very heavy rainfall over sub-Himalayan West Bengal and Sikkim on May 20 and 21 and Assam and Meghalaya on May 21.
IMD is expecting extensive damage to thatched houses, some damage to old, ramshackle concrete structures; uprooting of communication and power poles, disruption of rail/road links at several places, extensive damage to standing crops, plantations and orchards. Large boats may get torn from their moorings.
NDRF has 15 teams in Odisha; 19 in West Bengal and two in reserve for rescue and relief efforts.