Explanation:

Following atmospheric and oceanic conditions are necessary for development of a cyclonic storm. (This is called as formulation stage)- 

(i) A warm sea temperature in excess of 26 degrees centigrade to a depth of 60 m, which provides abundant water vapour in the air by evaporation. 

(ii) High relative humidity of the atmosphere to a height of above 7,00 m facilitates condensation of water vapour into water droplets and clouds, releases heat energy thereby inducing a drop in pressure. 

(iii) Atmospheric instability encourages formation of massive vertical cumulus cloud convection with condensation of rising air over ocean.