A large number of western cyclonic disturbances are formed over the Mediterranean Sea every winter. These disturbances are strong wind systems, strong enough to produce rainfall in the form of thunderstorms.
The wind system about these disturbances is cyclonic in nature i.e. anticlockwise. Hence they are named western cyclonic disturbance by meteorologists.
Many of the westerly oceans which extend into high latitudes during the winters, play an important role in bringing up these disturbances to the Indian subcontinent.
Tropical cyclones originate over the Bay of Bengal and the Indian ocean. These tropical cyclones have very high wind velocity and heavy rainfall and hit the Tamil Nadu, Andhra Pradesh and Orissa coast.
Most of these cyclones are very destructive due to high wind velocity and torrential rain that accompanies.
