There may be numerous DCA-JFK flights a day, but there's only one prior to the one he already is scheduled on. My suggestion is to check the weather forecast on the day before your scheduled departure. If it looks iffy, post back here then and we can advise you on the likelihood of making the earlier flight on a standby basis and how to go about doing so.

As for the suggestion that you consider an AA challenge, there's no harm in researching what it's all about, but if you avoid flying as much as possible, it likely is not worth the fee involved to do a gold or platinum challenge.