These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean.
An average of five tropical cyclones form in the North Indian Ocean every season with peaks in May and November.
It executed an anticyclonic loop to the west, and became a tropical storm before hitting eastern Sri Lanka on the 17th.
On October 18, a storm equivalent with windspeed of 85 kmph hit the state of Andhra Pradesh, dissipating the next day.
A storm of unknown intensity persisted in the western Bay of Bengal from December 3 to the 7th, remaining well offshore of any landmass.