How cyclone are form?

Fast moving air towards a centre; usually with heavy rain; is known as cyclone. Wind direction, wind speed, humidity and temperature together create cyclone.
When water vapour in the clouds cools down it releases heat. This heat warms the air around the clouds. The warm air rises up and creates a low pressure zone. This low pressure zone is quickly filled in by cooler air from the surrounding. This creates a system in which the centre is having very low pressure and is surrounded by wind moving around it. The wind from the surroundings moves in a circular fashion towards the centre and gives rise to cyclone.
The centre of the cyclone is called ‘eye’. A cyclone may be 10 to 15 km high. It is a rotating mass of air. The diameter of eye may be vary from 10 to 30 km. Eye of a cyclone is a calm area, but around the eye air may move with high speed such as 150 to 250 km/h.