Maybe TWC feels vocal music isn't fitting for a hurricane or something? It is odd that even TWC thinks the vocals are tacky when they have many viewers so they're backing off the vocal music for now. I just find that suspicious, especially if the vocal music returns immediately after the Isaac hype dies.
That's what I was going to say!
I personally think it's pretty irreverent to have this up-beat "life is good" kind of vocal music when a hurricane is about to threaten lives and property. It just isn't fitting, so they switch to instrumental music for the time being. I also have a good feeling that vocals will return after they are out of "red mode."
(Of course, one thing that could
really fix this problem would just be to use the Storm Alert music!!
)