Dhaka Courier

The anatomy of Amphan

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Cyclone Amphan on May 20, 1PM IST (12.30PM BdST). NASA.

On May 13th, an area of low pressure developed over the southeastern Bay of Bengal about 1020 km (635 mi) to the southeast of the important port city of Visakhapatnam in the Indian state of Andhra Pradesh. The area of low pressure was located within a favourable environment for further development, noted meteorologists in the earliest correspondence they engaged in over what eventually emerged as Cyclone Amphan (meaning amber we’re told, and leave the pronunciation), the name submitted by Thailand as part of a regional pooling initiative.

Over the next couple of days, the system became more marked as it gradually consolidated further, with bands of deep atmospheric convection wrapping into the system's low level circulation center. On May 16, the India Meteorological Department (IMD) reported that the area of low pressure had developed into a depression. Within hours, it became more organised as it kept moving north and became a cyclonic storm. By then the word had gone out already and even in the midst of the otherwise all-suppressing COVID-19 situation, that both countries in Amphan’s crosshairs found themselves knee-deep in already, the response at all levels - government, community, and NGOs - started mobilising.

By now it is a pretty familiar drill. The thousands of Red Crescent volunteers went into the communities, stressing the importance of paying heed to the government’s directives, particularly as they related to evacuations. The shelter centres were prepared to house them, both purpose-built cyclone shelters as well as ad hoc ones adding up to a total of over 12,000 such places this time around. In the event, over 2.4 million people, including 850,000 children under 18, were evacuated from the most dangerous areas. The government also allocated 3,100 metric tons (MT) of rice and 42,000 packets of food along with funds for children’s food ($36,400) and animal feed ($32,900) and US$ 58,700 in cash to 19 risk-prone districts, that will be allocated at the local administration’s discretion. Which judging by some recent incidents during the pandemic is not at all reassuring.

Meanwhile out in the Bay, on May 17, conditions for significant intensification became more likely as the southern shear (which had previously restricted any sort of intensification) began to clear, and the shear situated to the north moved further inland. Subsequently, Amphan became a severe cyclonic storm, and then began to undergo explosive intensification, according to the Joint Typhoon Warning Center (JTWC) of the US Navy. Amphan’s 1-minute sustained winds increased from 140 km/h (85 mph) to 215 km/h (130 mph) – equivalent to a Category 4 hurricane on the Saffir-Simpson scale – in only six hours that day.

By the 18th, which is about the day it became the first non-Corona topic to have sustained any staying power against the onslaught of the virus - just as something for a nation to ponder collectively, or even just observe or keep tabs on - the intensification in the Bay had continued, such that many of us first heard of it as not just a cyclone, but an impending ‘Super Cyclone’. Just what the country needed! By now, the pandemic has caused most people to pull out the prayer rugs, this was the cue for the rest. Phones became flooded (pardon) with messages of collective and undeserved doom for a nation that only God could save now.

Whether it was their prayers, or Amphan’s inability to complete a fascinating eyewall replacement cycle it had started earlier that would have sustained far more intensity, something did smile down upon us that very day, as late on May 18, the northwestern portion of the eyewall began to collapse as a result of dry air intrusion. Additionally, increasing wind shear due to monsoonal movements meant that the system's eastern quadrant was continually being degraded,robbing it of symmetry, which was generally the theme throughout the 19th.

The next day, May 20, around 6PM in Bangladesh, Amphan made landfall near Bakkhali, West Bengal with winds of 155 km/h (100 mph). As it moved further inland, it rapidly weakened and just six hours after landfall, the JTWC downgraded it to a Category 1-equivalent cyclone and issued its final warning on the system as it became disorganised.

Aftermath

Wide swathes of the coasts of India and Bangladesh were flooded and millions of people remained without power through Thursday, a day after after the most powerful cyclone to hit the region in more than  decade left dozens dead and a trail of destruction.

In the Indian city of Kolkata, home to more than 14 million people, large portions of the metropolis and its suburbs were underwater, including the city’s main airport. Roads were littered with uprooted trees and lamp posts and electricity and and communication lines were down.

Cyclone Amphan also badly damaged many centuries-old buildings when it tore through the city on Wednesday, May 20.

“It feels like a dystopian Jurassic Park of sorts,” said Shuli Ghosh, who runs a cafe in Kolkata, talking to the Associated Press. “The roofs of many homes have flown away and the streets are waterlogged.”

When the storm made landfall on Wednesday it lashed coastal areas in both India and Bangladesh with heavy rain, a battering storm surge and sustained winds of 170 kilometers per hour (105 mph) and gusts up to 190 kph (118 mph). It devastated coastal villages in both countries, knocking down mud houses, ripping out electricity poles and uprooting trees.

In Bangladesh, television stations reported 13 deaths, while 72 deaths were reported in India’s West Bengal state. Officials said two people were killed in India’s Odisha state. Hundreds of villages in Bangladesh were flooded by tidal surges and more than a million people were without electricity. Officials in both countries said the full extent of the damage remained to be seen as communication lines to many places remained down.

The ongoing coronavirus pandemic and social-distancing measures had made mass evacuations ahead of the storm difficult. Shelters were unable to run at full capacity in many places and some people were too scared of the risk of infection to mass there. Likewise the pandemic will have an impact on relief efforts and the recovery. The damage caused by the storm is likely to have lasting repercussions for poor families already stretched to the limit by the economic impact of the pandemic.

A preliminary report of the Needs Assessment Working Group (NAWG)- that is convened at field level to coordinate the activities of the UN-affiliated agencies, and mandated by the Office for the Coordination of Humanitarian Affairs, or OCHA- suggests the hardest hit districts are Khulna, Jessore, Satkhira, Bagerhat, Pirojpur, Barguna, Patuakhali, Bhola and Noakhali.

It is estimated that as many as 500,000 families may have lost their houses due to collapsed embankments and tidal surges. Nearly a million people across 12 districts have been left without electricity. Initial reports indicate that emergency shelter assistance, WASH and livelihood support are required.

In Cox’s Bazar, preliminary reports indicate that damage is fairly minimal with some 300 houses damaged, of which 60 are fully destroyed. Flooding and small landslides as well as blocked drains and damaged stairs, latrines and bridges have been reported in several camps. At this stage, there are no reports of casualties or deaths.

  • Bay of Bengal
  • Super Cyclone
  • Amphan

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