The basic requirements for the formation of cyclone are as mentioned:
1. Large and continuous supply of warm and moist air.
2. Strong Coriolis force.
3. Unstable condition through the troposphere that creates local disturbances around which a cyclone develops.
4. Absence of strong vertical wind wedge.
In central and western India, the droughts are more frequent because of the following reasons:
1. The monsoons do not occur in these areas frequently.
2. The rainfall is about 75 cm per annum.
3. The intensity of monsoon winds becomes weak as they reach in these areas.