NOAA’s National Hurricane Center does not control the naming of tropical storms. Instead, there is a strict procedure established by the World Meteorological Organization. For Atlantic hurricanes, there is a list of male and female names which are used on a six-year rotation. The only time that there is a change is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate. In the event that more than twenty-one named tropical cyclones occur in a season, any additional storms will take names from the Greek alphabet.