JOIN USCyclone Amphan: Unusually warm Bay of Bengal made it a super storm in 18 hours
An unusually warm Bay of Bengal has fuelled the severity of Cyclone Amphan converting it from an ordinary storm to super cyclone within a span of just 18 hours.
The storm will lose some of its steam when it approaches the shore and is likely to make a landfall on Wednesday evening between Digha (West Bengal) and Hatiya Islands (Bangladesh) close to Sundarbans with a speed of 155-185 km per hour.
At least 12 districts of West Bengal and Odisha will bear the brunt of it as the two coastal states are set to be rattled by the impending storm.
"This is the most intense cyclone - the second super cyclone - which has been formed in Bay of Bengal after 1999. Its wind speed in the sea right now is 200-240 kmph," Mrutyunjay Mohapatra, director general of India Meteorological Department said here.
Weather scientists tracking the storm were surprised by an unusually warm Bay of Bengal, which led to packing of a huge quantity of moisture into the cyclone, making it a big one.
"Bay of Bengal recorded surface temperatures of 32-34°C, prior to the cyclone Amphan. We have never seen such high values until now," said Roxy Mathew Koll, a weather scientist at the Indian Institute of Tropical Meteorology, Pune.
Tropical cyclones draw their energy from the ocean surface and these temperatures can supercharge a cyclone, leading to its rapid intensification.
"Cyclone Amphan intensified from a category-1 cyclone to category-5 cyclone in a short span of 18 hours. It evolved into the strongest cyclone ever recorded in the Bay of Bengal," he said.
"Clear (cloud free) skies and low wind conditions assist in building high sea surface temperature values. But definitely they are riding on a global warming background. We have not seen such peaks earlier," Koll told DH.
On landfall, Amphan's intensity would be somewhat similar to Cyclone Fani (2019) that had a wind speed of (155-215 kmph). It killed 72 persons in India and caused damages worth 120 billion rupees.
The IMD has forewarned that gale wind speed reaching 155-185 kmph is very likely along and off east Medinipur and north & south 24 Parganas districts of West Bengal.
The wind speed will be marginally less (110-130 kmph) over Kolkata, Hoogli, Howrah and west Medinipur at the time of landfall.
For the north Odisha districts, the wind speed will be in the range of 100-125 kmph.
As many as 34 battalions of the National Disaster Response Force have been deployed on the two eastern states whereas another 8 battalions are on standby.
Telecom companies have been asked to arrange for power generators so that towers can be brought alive quickly even after electricity failure.
The two states have evacuated lakhs of people living in the affected districts.