Cyclones in India originates in both sides Arabian sea as well as Bay of Bengal ,
Bay of Bengal is prone to Cyclones because of numerous reasons:-
There is an upper air jet stream that blows in easterly direction towards the north of Tibet along the kolkata bangalore axis.
These upper air easterlies descend into the permanent high pressure area formed over the southern Indian Ocean. The Tropical Easterly Jet (TEJ) shifts its position with the position of the ITCZ. By the end of September
it is firmly establishes along an east to west direction.
Other factors are also favourable too:-
1.The ideal temperature is aroun 25-27 degree celcius .This temperature helps to sustain moisture,
and Bay of Bengal is more warmer than arabian sea,and warmer sea attract cyclones.
2.Wind shear is the change in wind speed,they are o are 2 types horizontal and vertical
The horizontal wind shear is the change in wind-speed wrt to latitudes and the vertical wind is the change in the wind-speed wrt to altitude( height).
For a tropical cyclone like the ones in Bay of Bengal to form, we need to have a relatively lower vertical wind-shear.
This effectively means that lower the difference in the speed of the wind wrt altitude, then greater is the chance of formation of a cyclone.
Again, Bay of Bengal offers this advantage.
3. whenever Bay of Bengal experiences a cyclone ,there would be south china sea facing a typhoon.and the leftover moisture would passover to Bay of Bengal.
4.The coromandel coast does not have greater mountains to block the ferocius winds of
cyclones in eastern ghats.Cyclones need larger room to grow.
Western ghats have larger mountains and thier range is also greater than eastern ghats.
5. Cyclones in India are erratic the retreating monsoon is also erratic in nature than the normal monsoon,for a cyclone to get formed all the above factors should be present.