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Cyclone Yaas churning toward India at hurricane strength, landfall predicted Wednesday


Cyclone Yaas hit hurricane strength in the Bay of Bengal on Tuesday, gaining force as it churns toward India and prepares to make landfall Wednesday morning local time. Strong winds, flooding rains and a coastal storm surge, or risen in ocean water above normally dry land, are possible as Yaas becomes Indias second landfalling tropical cyclone in a week and a half.

Just last Monday, "extremely severe cyclonic storm" Tauktae raked Gujarat, north of the Arabian Sea on India's west coast, with Category 3 gusts well over 100 mph. Nearly 100 were killed by the storm, which caused more than $2.1 billion in damage.

The back-to-back storms come as India's covid-19 death rate continues to sit at more than 4,000 a day, with the nation of more than 1.3 billion people now a global epicenter of the unrelenting pandemic.

As of Tuesday evening local time, Yaas had winds of 75 mph, crossing the threshold of a low-end Category 1 hurricane equivalent. It was about 150 miles south of Kolkata in West Bengal, along India's northeast coast, or roughly south of the India-Bangladesh border. The storm was moving slightly west of due north at 10 mph.

On satellite imagery, a region of strong thunderstorms can be seen making up the "central dense overcast," or core, of the storm, within which strong winds and heavy rainfall are ongoing. Along the periphery of the storm, healthy outflow, or exhaust, can be seen evacuating air at high altitudes to allow the storm to intensify.

Tens of thousands have been evacuated inland. India has stepped up its advanced preparation procedures considerably in the past two decades after roughly 10,000 people perished in the 1999 Odisha Cyclone.

Maximum wave heights offshore could exceed 60 feet; that prompted the India Meteorological Department to issue a warning for mariners "not to venture into central Bay of Bengal during 24th-25th May."

The agency also issued wind and storm surge warnings, noting the potential for serious damage to vulnerable infrastructure in Odisha and West Bengal.

"Total destruction of thatched houses [and] extensive damage to kutcha houses" is possible, wrote the India Meteorological Department, along with a "potential threat from flying objects."

They also noted the risk of damage to communication lines, disruption of rail travel and transportation systems and the destruction of crops, such as coconuts, palms and mango.

Yaas is expected to make landfall Wednesday morning as a high-end Category 1 or a Category 2 storm, maintaining current strength or increasingly in intensity slightly. That means winds along the immediate shoreline could gust upward of 90 mph. The India Meteorological Department is calling for "extremely heavy rainfall" with up to 8 inches in spots.

Some cities near or just west of Yaas's center could pick up as much as a foot, especially places west of Kolkata, like Bhubaneswar and Cuttack. While the region is accustomed to hefty monsoonal rainfall with average totals of 100 inches or more, the rapidity with which rain may fall early Wednesday could bring instances of urban flooding.

Potentially more concerning is the propensity for coastal inundation associated with Yaas's storm surge. While the storm isn't overly powerful in comparison to other cyclones India has dealt with, the slope of the sea floor, known as bathymetry, will enhance the threat of dangerous storm surge flooding. The Bay of Bengal has an extensive continental shelf, meaning the sea floor is relatively shallow, making it easier to displace larger amounts of water inland.

"Tidal waves of height 2 to 4 meters above astronomical tide are likely to inundate low-lying areas of Balasore [and] Bhadrak," stated the India Meteorological Department.

Any surge will make it more challenging for rainfall to drain out of rivers like the Hooghly, exacerbating flood concerns even more.

Rahul Ghandi, a member of the Indian Parliament, took to Twitter to plead with fellow politicians to allocate funds and resources to aid in preparation and evacuation efforts.

"I appeal to Congress workers to provide all assistance ensuring safety of those affected," he wrote.

 

Yaas will weaken as it moves inland, largely dissipating from a wind perspective by Thursday. Heavy rainfall will continue inland and affect much of the high terrain approaching the Himalayas.

Published : May 26, 2021

By : The Washington Post · Matthew Cappucci