There are seven tropical cyclone "basins" where storms occur on a regular basis:
1. Atlantic basin, including the North Atlantic Ocean, the Gulf of Mexico, and the Caribbean Sea
2. Northeast Pacific basin.from Mexico to about the dateline
3. Northwest Pacific basin.from the dateline to Asia including the South China Sea
4. North Indian basin, including the Bay of Bengal and the Arabian Sea
5. Southwest Indian basin.from Africa to about 100E
6. Southeast Indian/Australian basin (100E to 142E)
7. Australian/Southwest Pacific basin (142E to about 120W)

According to NOAA's National Hurricane Center, approximately 69 percent of the tropical cyclones occur in the Northern Hemisphere, while only 31 percent can be found in the Southern Hemisphere. Approximately 12 percent occur in the Atlantic Ocean, 57 percent occur in the Pacific and the remaining 31 percent occur in the Indian Ocean.
In June 2003 we started providing global near-real time estimates of tropical cyclone heat potential in the seven basins during all year.