October Storm in Bay of Bengal


    In News 

    • The first Tropical Cyclone of the post-monsoon season of 2022 is likely to form in the Bay of Bengal on October 24 and will be called Sitrang.
      • The last October cyclone in the Bay of Bengal was Titli in 2018.


    • The months of October-November and May-June see storms of severe intensity develop in the North Indian Ocean — comprising the Bay of Bengal and the Arabian Sea — with an average of five developing in a calendar year. 
    • In the past 131 years, October saw 61 storms develop in the Bay of Bengal.
      • In comparison with the Bay of Bengal, only 32 storms have developed in the Arabian Sea in October since 1891.

    Major Reasons 

    • After the withdrawal of the Southwest monsoon, there is a rise in ocean heating, which leads to rise in sea surface temperature over the Bay of Bengal. 
    • The atmospheric moisture availability over the ocean region, too, is higher.
      •  So, when remnant systems from the South China Sea reach the Bay of Bengal, they get conducive conditions, aiding the formation and intensification of cyclones in October,” 
    • In some years, ocean-atmospheric factors hinder this phenomenon. 
      • For instance, in 2020, weak La Nina conditions along the equatorial Pacific Ocean prevented a cyclonic formation near India’s coasts.

    Cyclone Sitrang

    • The name Sitrang (read Si-trang) has been given by Thailand, and features in the list of tropical cyclone names prepared by the  Regional Specialised Meteorological Centre (RSMC) being followed since April 2020. 


    • The prevailing low pressure system will strengthen and move towards India’s east coast in the coming four days.
    • Gale winds and enhanced rainfall are expected mainly over Andaman and Nicobar islands, Odisha, West Bengal and Bangladesh, particularly the coastal districts.

    Tropical cyclone 

    • It is a rapid rotating storm originating over tropical oceans from where it draws the energy to develop. 
    • It has a low pressure centre and clouds spiralling towards the eyewall surrounding the “eye”, the central part of the system where the weather is normally calm and free of clouds.