This the first hurricane I have watched on GOES, so I am just guessing. It will be interesting to see if you can tell the future track from the water vapor images.
Isn't it called "Occam's Razor"? You look at the most obvious explanation of something, and it's probably the correct one, so prove or disprove it first.
Water vapor makes sense. You know how when you're near the ocean you can sometimes feel when that storm is heading in or going out to sea? Well, wouldn't that be water vapor?
We'll see. It's always fun to see a new hypothesis play out. (Yeah, I'll admit it. Hurricanes are incredible fun unless and until there is horrific damage. Walking along the ocean, feeling that breeze and surf, staring at the maps and the ridiculous WeatherStation announcers on the shore telling people it's dangerous to be on the shore, buying emergency twinkies or whatever...like anyone would starve in two days, seeing my neighbors golf-course like lawns and gardens get decimated, the break in the schedule, etc, etc)