Typhoons are caused by the cycle of warm air heated by the warm sea water rising, cooling and then being pushed aside by more warm air rising from below. This cycle causes strong winds as air rises quickly when heated by warm sea water. When the winds reach at least 74 miles per hour, the phenomena is considered a tropical cyclone, or typhoon.
A typhoon is a regional name for a tropical cyclone. When sustained winds reach 74 miles per hour in the Northwest Pacific Ocean west of the dateline, the phenomena is labeled a typhoon. When this occurs in the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline or the South Pacific Ocean east of 160E, then it is called a hurricane.
When cyclones are severe and sustained winds reach more than 110 miles per hour, they are classified as severe and are referred to as a Category 3 cyclone.
Typhoons and other tropical cyclones only occur at a distance of at least 300 miles from the equator and in sea water that is at least 80 degrees Fahrenheit.
Responsibility for monitoring typhoons, cyclones and hurricanes is determined by the ocean in which the storm developed and is divided among various national meteorological associations.