If realised, Cyclone Sitrang will be the first cyclone to develop in the Bay of Bengal in October since 2018, and will be called Sitrang, as named by Thailand. The last October cyclone in the Bay of Bengal was Titli in 2018.

 

Details

  • 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, according to the Regional Specialised Meteorological Centre (RSMC).
  • The east coast, notably Odisha, has faced many of its severest storms in October, including the Super Cyclone of 1999.

 

Formation

  • 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.

Cyclones in the Arabian Sea

  • In comparison with the Bay of Bengal, only 32 storms have developed in the Arabian Sea in October since 1891.
  • Climatologically too, the IMD states that of the five storms formed in the North Indian Ocean in a calendar year, four are in the Bay of Bengal and one in Arabian Sea.