India is exposed to nearly 10% of the world’s tropical cyclones, thanks to a long coastline of 8,041 kilometres. On an average, five to six tropical cyclones form every year, of which a couple of them could be destructive.
The Super Cyclonic Storm of 1999 that caused immense destruction in Odisha is a stark reminder that Indian seas are the deadliest basins for formation of sever cyclones. Though, Phailin was the strongest tropical cyclone that ever made landfall in India after this, destruction in terms of life and property was negligible in comparison to the former cyclone.
The cyclones with severe intensity peak in the months of October or November (Cyclone Phailin) and the ones of less intensity develop in May (Cyclone Mahasen).
Majority of cyclones in India have their genesis over the Bay of Bengal and thus, strikes the east coast of India. The ratio of cyclones occurring in the Bay of Bengal to the Arabian Sea is approximately 4:1. An analysis of the frequency of cyclones on the east and west coasts of India between 1891 and 1990 shows that nearly 262 cyclones occurred on the east coast and 33 cyclones occurred on the west coast during this period.
Cyclones originating in Arabian Sea
The western part of the Arabian Sea is cooler and thus, not conducive for formation of cyclones. Gujarat is the main pocket to get threatened from the Arabian Sea and witnesses about 70% of the cyclones. 10% of them hit Maharashtra coast while rest of them drifts away to Oman or Pakistan.
Cyclones originating in Bay of Bengal
Bay of Bengal is more prone to intense cyclones with 65% of them striking the Indian coast and 25% drifting away to Myanmar or Bangladesh. 10% of Cyclones dissipate into the sea due to cold waters, strong wind shear or if they come in proximity to the equator.
Andhra Pradesh, lying in the east coast of peninsular India, is the worst hit by cyclones every year. Odisha and Bengal bear the brunt of cyclones in October, Andhra Pradesh in November and Tamil Nadu in December.