In the month of October, the Southwest monsoon retreats. The sea surface temperatures are still high, wind shear also remains low.
Most of the tropical cyclones to strike the Indian coast originate either in the Bay of Bengal or the Arabian Sea. Usually, the number of cyclones forming in the Bay of Bengal is more. Sometimes these cyclones start out as low-pressure areas or remnants of Pacific cyclones in the Gulf of Thailand and traverse the Andaman Sea and usually re-intensify in the Bay of Bengal.
The Equatorial seas remain warm all year round, but the Bay of Bengal begins to cool down by around November, impeding the development of severe storms. Therefore, October is one of the most active months for formation of cyclones in the Bay of Bengal.
This year in the month of October, one low pressure has already formed. Another low pressure will travel to the Bay of Bengal by 9th October from the Gulf of Thailand. This weather system has the potential to intensify into a depression and may affect Odisha and Andhra Pradesh. There seems to be a series of low pressure developing in the Bay of Bengal this month as another low may enter the Bay of Bengal by October 16th. That will be the third weather system in the Bay of Bengal this month. We must wait and check if any other weather system forms over the Bay of Bengal this October or not.
The movement of cyclones which forms over the central part of the Bay of Bengal is usually in West-Northwest or Northwest direction towards Andhra Pradesh and Odisha coast. Sometimes they recurve in northeast direction after reaching near the coast and it travels towards Gangetic West Bengal, Bangladesh or Myanmar.
Temperatures start dropping in Northern and Central parts of Bay of Bengal in the month of November. But as the temperatures of southern parts of the Bay of Bengal remains warm in November. Therefore, the formation of low-pressure areas, depression as well as cyclones also shifts towards the south Bay of Bengal. They tend to develop in the south-east Bay of Bengal and travel in West-Northwest direction towards Tamil Nadu for south Andhra coast.
Odisha Cyclone 1999, Onil in 2004, Phalin in 2013, Hudhud in 2014 and Titli in 2018 all formed in the Bay of Bengal in October.