Question

what is the main reason to come cyclone​

Answer 1

cyclone is caused when there is high pressure because then air moves rapidly from high pressure to low pressure and thus form cyclones.
hope this helps you friend....

Answer 2

Tropical cyclones form only over warm ocean waters near the equator. To form a cyclone, warm, moist air over the ocean rises upward from near the surface. As this air moves up and away from the ocean surface, it leaves is less air near the surface.

which causes cyclone to form