There is a tendency for dialects to “shift” as you cover geographic ground. The distinction between two dialects is not so much a clear change as it is a slow slidefrom one stereotypical dialect to another… There is drift. And any attempt to say “This is the _____ dialect” is inherently inaccurate because a dialect is, by definition, a generalization based on a number of “ideolects” or individual’s dialects.
Here’s a recording of a man from Bricktown, New Jersey. You can hear a little bit of that stereotypical New York City/New Jersey sound, but it’s drifted away from there because of the distance (and possibly due to other influences on this person, such as education and work.) It’s about a 70-mile drive from NYC south to Bricktown.
You could say that he has a Bricktown dialect, a New Jersey dialect, or you could get even more general and say he has an east coast dialect. Dare I even say an American dialect? But that’s getting far too general to be useful… Keep in mind that even in Bricktown you’d probably hear natives who sound completely different from this man…
