Why so many cyclones in May?
Weather conditions in May create a perfect recipe for cyclones in the Bay of Bengal.
Since no low pressure has been created in the Bay this year, the heat energy has accumulated, and this may turn cyclone Mocha into a super cyclone, according to officials at Bangladesh Meteorological Department (BMD).
From 1891 to 2022, a total of 530 cyclones formed in the Bay of Bengal, and 65 of those happened in the month of May, they said.
The cyclones formed in May make landfall mostly in Myanmar. Fewer cyclones make landfall in India and Bangladesh.
In Bangladesh, these cyclones make landfalls in Sandwip, Hatiya, Chattogram, and Cox's Bazar, BMD officials have said.
"The sea surface temperatures rise in May and create wind shear. The difference in wind speed between the upper and lower levels widens creating the perfect conditions for cyclogenesis to occur," Muhammad Abul Kalam Mallik, meteorologist at BMD, told The Daily Star.
The sea surface temperature remains 25-28 degrees Celsius, but now it is over 30 degrees Celsius, he added.
"There will be major impacts both ahead and after landfall for potentially hundreds of thousands of the world's most vulnerable people." Clare Nullis
The condition for cyclone formation includes a temperature of over 27 degrees Celsius from a depth of 60 metres to the surface of the sea and a humidity of over 40 percent.
The cyclones that happen during this time of the year usually leave a trail of destruction, BMD officials say.
In the Bay of Bengal, cyclones mostly form during pre-monsoon and post-monsoon periods due to the sea surface temperatures and the pre-monsoon ones often turn severe in nature.
Mostofa Kamal Palash, a weather and climate researcher at the University of Saskatchewan in Canada said the sun starts moving towards the northern hemisphere in March and lies directly above the Tropic of Cancer at the summer solstice, which usually falls on June 21.
"In May, the sun lies directly over the middle of the Bay of Bengal, which helps increase the sea surface temperature and the ocean heat content, both of which serve as the primary ingredients needed to form tropical cyclones.
When these happen simultaneously, a cyclone becomes very energetic and occasionally becomes a super cyclone, he added.