Define the western disturbances and their effect on India.

Western disturbances are cyclonic depressions that take place over Andaman and Nicobar Islands as also over the East Mediterranean sea. These travel eastwards across Iraq, Iran, Afghanistan and Pakistan before they reach the north-western parts of the country. They receive moisture while blowing over the Caspian Sea in the north and Persian Gulf in the south.

The western disturbances are preceded by warm weather or sudden rise in temperature. These cause light rainfall in the northern plains of India. These cause snowfall in the northern Himalayas. The rainfall as also snowfall of winter season are beneficial to the rabi crops i.e. wheat, barley etc.