Usually, one of the water parks close in late fall/winter for refurb (as has already been posted). Also usually, they alternate years between the two.
Last year, Typhoon Lagoon was scheduled to be closed for refurbishment October 26, 1008 - March 22, 2009. I don't recall whether they kept exactly to that schedule or not, but it was probably close.
So, unfortunately for you, it is likely to be Blizzard Beach that is closed this year for approximately the same time period.
But at least you'll be able to visit Typhoon Lagoon. It's pretty good, too. Each has its own strengths and weaknesses. I actually prefer the Typhoon Lagoon lazy creek.
You may get lucky and have BB open the first day or so you are there, but that is a long shot. I can't find anywhere where the refurb schedule has been announced yet.
And being from New Jersey, I can tell you that it will probably quite pleasant for swimming in November for somebody from colder climes. The water will be heated, and in November, although they have their cold snaps, the normal high is 26 C. If you are lucky, a bit warmer. If you are not so lucky, perhaps below 20 C.