This prophecy, as best I understand it, is meant to be a sign, with God using it to demonstrate His power to the world. However, unlike any other whirlpool before it, this one will be so massive, so massive, so unusual, that it will defy explanation. The exact location where this is supposed to be, and how long it'll last is not known. At least not yet.
(*Do you have a better description, or did you find an error? Please let me know.