What is a monsoon?
A monsoon is a seasonal shift in the prevailing wind direction, that usually brings with it a different kind of weather. The persistent wind flow is driven by a warm air mass with low pressure at the surface that forms over the continent as it is warmed by the sun. Air from the relatively higher pressure air mass over the ocean flows toward the low pressure over land. Probably the most famous monsoon is the Indian summer monsoon, as it affects such a large portion of Asia. In May and June of each year, the dry northerly wind flow over India changes direction, and warm humid air from the Indian Ocean flows from the south, gradually overspreading the Indian subcontinent. Widespread torrential rains, and even severe thunderstorms, accompany the “onset” of the monsoon. The Indian Ocean version of the hurricane, called a “cyclone”, can also occur and move ashore in association with the onset of the monsoon. These cyclones have at times killed thousands of people who live in the low-lying ar
