(NewsNation) — The National Oceanic and Atmospheric Administration is predicting up to four major hurricanes this season, and they’ve released the latest list of hurricane names. But how did the tradition of naming hurricanes begin, and who decides what to name them?

The practice of naming hurricanes began as a way of avoiding confusion. Because multiple hurricanes can be forming at once, using names makes it easier for meteorologists and the public to distinguish between predictions about the storms.

Initially, tropical storms were named after the saint’s day the hurricane occurred on. But in 1953, the U.S. began using women’s names for storms, and 1978 they expanded the list to add male names. The names are in alphabetical order, alternating between male and female. While there are 26 letters in the alphabet, there are only 21 names on the list because there aren’t enough common names beginning with the letters Q, U, X, Y or Z to include them.

The list of names is determined by the World Meteorological Organization. There are six lists of names that rotate through, but names can be retired. That happens when a hurricane is so severe and deadly it would be inappropriate and confusing to continue to use the name.

Just a few of the retired names include Floyd (1999), Harvey (2017), Katrina (2005) and Ida (2021).

This year, the NOAA released the list of names for the upcoming season, which are: Arlene, Bret, Cindy, Don, Emily, Franklin, Gert, Harold, Idalia, Jose, Katia, Lee, Margo, Nigel, Ophelia, Philippe, Rina, Sean, Tammy, Vince and Whitney.

The list only applies to storms that form in the Atlantic; a separate list is maintained for storms forming in the Pacific basin.

So what happens if there are more tropical storms than names on the list? The World Meteorological Organization also keeps a list of backup names. Those don’t rotate and can be used if the season extends to more than 21 storms in the year.