A look into the interesting process of naming hurricanes.

Sadly, Harvey and Irma have already become household names as America copes with two monstrous late summer hurricanes. But where, exactly do these names come from and who names the storms in the first place?

If you’ve ever been curious on the storm-naming process, there’s a fascinating backstory. At first, storm names were decided at random—hundreds of years ago, hurricanes were even named after saints, according to the National Oceanic and Atmospheric Administration or NOAA. Now, the process is very regimented.

“Since 1953, Atlantic tropical storms had been named from lists originated by the National Hurricane Center,” reads the NOAA’s website. Interestingly, from 1953 to 1978, hurricanes were only given female names, before men’s names entered the lineup in 1979. “They are now maintained and updated through a strict procedure by an international committee of the World Meteorological Organization,”

The committee determines names for Atlantic hurricanes using six lists for upcoming years (currently, the lists run from 2017 to 2022). Each list has 21 names that are cycled through in alphabetical order and are added back into rotation after six years (that means this year’s list will be used again in 2023). Names on the list alternate between male and female appellations. If more than 21 storms strike, names are used from the Greek alphabet.

Additionally, some names do get retired from the lists. “The only time that there is a change in the list is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate for reasons of sensitivity. If that occurs, then at an annual meeting by the WMO committee (called primarily to discuss many other issues) the offending name is stricken from the list and another name is selected to replace it,” states the NOAA. Some retired names you may recognize from recent years include Katrina, Rita, Sandy, Joaquin, Irene, Matthew, and Otto.

WATCH:  Houston Strong: See Incredible Everyday Heroes Help Save Lives Through Hurricane Harvey

For Irma’s specific lineage, it’s simply the 9th storm name on the WMO’s list, after Harvey and before Jose. Previously, the name “Irene” was in rotation. Irene, however was removed after a 2011 storm by that name wreaked havoc on New Jersey, New York, Massachusetts, and Vermont. Irma is a new name for 2017 in its place. Currently, it is unclear if Harvey and Irma will be added to the list of retired names.

To geek out on more hurricane naming history and retired name information, read the National Hurricane Center’s post here.