Re-reading your comment, and mine, I realize that mine probably sounds unduly harsh/overbearing. Sorry about that. It’s clear, as I read it with fresh eyes, that you were simply confused about the status of Alma/Arthur. If I didn’t already make this clear, Alma was Alma in the Pacific, and then she (or rather, her remnants) became Arthur in the Atlantic. That isn’t always the case with a storm that crosses from one ocean basin to the other, but it was the case in this instance, and I’ve heard no suggestion that it should have been otherwise. The NHC followed its storm designation rules pretty closely and clearly in this instance.
Also, as I said, if Alma had remained Alma, instead of becoming Arthur, then she wouldn’t have counted as an Atlantic storm at all, and Bertha would have been Arthur. The name list never simply skips a letter.
