Can't help you with the Caribbean station, but I can tell you that the only other station besides WGN I've heard here in Ohio was a daytimer in North Carolina that stayed on well past its hours last September when a hurricane came through. I usually hear that station giving WGN fits at critical hours, but never later. It packed quite a punch into Ohio until WGN finally overtook it an hour or so after dark.
In any case, this probably wasn't the station you heard. It was quite definitely Southern, drawing from the thick accents (drawls?) of its announcers.
> What is the Caribbean sounding talk station coming over 720
> AM, no music so far. WGN usually bleeds an oldies station
> during this type of stormy weather, this is unusual for the
> frequency. I'm in SE PA.