The letters used are:A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-R-S-T-V-W. (21 letters). If needed, they would actually use the letters of the Greek Alphabet after that.The year with the most documented tropical storms was 1933, when there were 21 in the Atlantic Basin, but this was before hurricanes were routinely named. Note that the naming starts only when a system becomes a tropical storm, it might not upgrade to a hurricane status.Tropical storm: winds between 39mph-73mph.With 2 more months to go ,this year could become a record year easily.