National Weather ServiceAll you need is warm ocean water and wind, and a few key ingredients can come together to create a tropical storm. There's a reason that such storms (e.g., cyclones, hurricanes, typhoons) always form over equatorial regions: that's where the warmest ocean water is located. When wind blows over that warm ocean water, it picks up not only heat but also moisture from the ocean. Kaidor / Wikimedia CommonsWhere you have fast-moving winds over the warm ocean, the air heats up, absorbs moisture, and rises. As winds in the column start to spin faster and faster, a tropical depression, tropical storm or even a full-fledged tropical cyclone (i.e., a hurricane) can form.

Source: Forbes August 28, 2017 20:25 UTC