I agree, if nobody has anything more to write about it, the article should be merged back in to 2005 Atlantic hurricane season.  The reason has nothing to do with notability (Alpha wasn't in any way notable, but that's not the point).  The reason is that this article should not exist if that article already has the exact same thing as a summary.  Only if the summary is shorter than the full text should the article exist.  However there's no need for an edit war here.  Since the storm is no longer active, making this decision isn't time-sensitive.  My suggestion is to add  to the article and give people a few weeks to write about it.