Here's What Happens If a Tropical Storm or Hurricane With a Greek Alphabet Name Needs to Be Retired

Atlantic tropical cyclone name lists repeat every six years unless a storm is so severe that the World Meteorological Organization (WMO) hurricane committee votes to retire that name from future lists. This avoids the use of, say, Harvey, Katrina, Maria or Sandy to describe a future weak, open-ocean tropical storm.

Since 1953, when the naming of Atlantic tropical cyclones ditched the phonetic alphabet, 89 Atlantic tropical cyclone names have been retired through 2018.

This year's exceptional pace of named storms has already crossed off Alpha, Beta, Gamma and Delta from the secondary list of Greek alphabet names. 2005 is the only other year when the naming of tropical storms and hurricanes had to dip into this backup list; There were six storms that received Greek alphabet names that year.

Following the 2005 season, the WMO hurricane committee met and decided to keep using the Greek alphabet names as a backup list each year. This was based on the fact that using Greek alphabet names would not be frequent enough to justify a change to this policy.

Instead, the committee opted to introduce a policy where if a tropical storm or hurricane with a Greek alphabet name needed to be retired, it would include the name along with the year of occurrence in its list of retired names. That Greek alphabet name would then continue to be available for any other times the backup list is used in the future.

Three of the six Greek alphabet names used in 2005 impacted land areas of the Caribbean and Central America. However, none of them caused enough damage for the newly created Greek alphabet name retirement policy to be used when the WMO committee met the following year.

It's likely we'll cross off one or more additional Greek alphabet names this year. An average season has produced three more named storms from early October through November, based on National Hurricane Center statistics from 1966 to 2009.

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