The names given to tropical cyclones that form in the Atlantic basin are predetermined by the World Meteorological Organization (WMO) with a set list for each year.
In every season, the first storm to form is given a name beginning with the letter A, while the second storm is given one starting with the letter B, and so on. This pattern continues until 21 letters of the alphabet have been used up. Q, U, X, Y and Z are left out due to the lack of names that start with these letters.
If the number of named storms surpasses 21 in a single season, protocol dictates that the letters of the Greek alphabet are used for all subsequent storms. These letters are: alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omikron, pi, rho, sigma, tau, upsilon, phi, chi, psi and omega.
Having more than 21 named storms in a season is incredibly rare. In fact, it has only happened once since the modern naming practice began in the mid-20th century—the record-breaking 2005 season, which saw 27 named storms, including the catastrophic Hurricane Katrina that devastated New Orleans.
But meteorologists say it is looking increasingly likely that the Greek alphabet will need to be used to name storms this year for only the second time in history, given the record-setting pace of the current season.
As of September 9, there have been 17 named storms in the Atlantic Basin, and this season is the first on record to see nine form before August and 13 before September. To put this into context, the average number of named storms in a season is 12.
On Monday, Tropical Storm Rene became the earliest Atlantic storm to form with a name beginning with the 17th letter of the alphabet. With only four names remain on the standard list for 2020—Sally, Teddy, Vicky, and Wilfred—there is a “pretty good chance” we will need to use the Greek alphabet for the additional storms, lead AccuWeather hurricane forecaster Dan Kottlowski told Newsweek.
“AccuWeather is forecasting up to 24 named storms this season. That will be an additional seven storms and there are only four names left on the list,” Kottlowski said.
The use of the Greek alphabet seems particularly likely when you consider that we are only just about to reach the meteorological peak of the hurricane season—September 10—and the fact October and November are typically active.
“As of September 8, we’ve burned through the ‘R’ storm, the 17th storm of the season. In an average hurricane season, we’d expect another 6 to 7 named storms to form before the season ends. With only four names left in the list, that would mean we’d burn through the second (beta) or third (gamma) letters of the Greek alphabet,” Jonathan Erdman, senior digital meteorologist at The Weather Company, told Newsweek.
“But that’s just an average ‘rest of the season.’ In the record 2005 hurricane season, we had to use the first six Greek letters for names, ending with Zeta that formed the day before New Year’s Eve.”
In fact, Kottlowski said the number of named storms in 2020 may turn out to be even higher than 24: “We could surpass 24 storms this year and challenge the number of named storms in 2005.”
