Of the cyclones hitting the coastal regions of the country, on average four out of five stampede the eastern shores of peninsular India.
According to the India Meteorological Department, this is because in addition to the storms that originate in the southeast Bay of Bengal and the adjoining Andaman Sea, breakaway typhoons over the Northwest Pacific move across the South China Sea into the Bay of Bengal, intensifying into cyclones.
As the frequency of typhoons over the Northwest Pacific is about 35% of the global annual average, the Bay of Bengal is affected.
“In contrast, Arabian Sea cyclones are mostly their own formations and they also generally move north-west, away from India’s west coast,” said Narasimha Rao, assistant meteorologist, Met Centre, Hyderabad.
Besides, the Arabian Sea is colder than the Bay of Bengal, which inhibits the formation and intensification of the cyclonic system in the former. Warm sea surface temperature is an ideal platform for cyclones.
While the incidence of cyclones is the highest on the Odisha coast, it is Andhra Pradesh that has suffered more.
During the period from 1891 to 2012, Phailin is the 74th cyclone to hit Andhra Pradesh. Of the 73 earlier cyclones, 30 hit the state in October, followed by 19 in November and nine in May.
No cyclones crossed the Andhra coast in January, February, March and April.
Apart from the cyclone of November 1977, when about 15,000 people died, the storm of May 9, 1990, killed around 1000 people. In the storm that struck on November 6, 1996, about 1,500 people died. Severe cyclones hit Odisha in 1971, 1977, 1990, 1996 and 1999.