Has the name Eta been retired?
Yes. The WMO Hurricane Committee retired Eta and Iota, both from 2020, at its March 2021 meeting, because of the death and destruction they caused (WMO Hurricane Committee retires tropical cyclone names and ends the use of Greek alphabet). There had been no formal plan for retiring Greek letters.
Eta is one of 100 names on NHC’s list of retired Atlantic names (Tropical Cyclone Naming History and Retired Names).
When will Eta be used again?
It won’t be. In March 2021 the WMO Hurricane Committee decided the Greek alphabet will not be used in future, because it distracted from warnings and some letters (Zeta, Eta, Theta) sound alike (WMO Hurricane Committee retires tropical cyclone names and ends the use of Greek alphabet). When the 21 regular Atlantic names run out, storms now take names from a supplemental list approved by the WMO, which starts Adria, Braylen, Caridad (Tropical Cyclone Naming History and Retired Names).
Why was the storm named Eta?
Names go in alphabetical order, one per storm, as each storm reaches tropical-storm strength (39 mph, 34 knots), so a storm’s place in its season decides its name.
In 2020, Eta was the 28th name used in the Atlantic season, after all 21 regular names.
In 2005 (Alpha to Zeta) and 2020 (Alpha to Iota), the regular list ran out and later storms took Greek letters in order.