When I hear the term "Gulf Coast", I think of Mississippi. When we were kids, every vacation was on the Gulf Coast. That might have been anywhere from Waveland/Bay St. Louis to Ocean Springs.

Florida has so much coastline that it's pretty much an entity unto itself. I guess the term Gulf Coast often refers to SE LA, MS, AL and NW FL. But in reality, it runs practically from Florida City all the way around to Brownsville.

When a storm is heading toward the (northern) Gulf Coast, there's also the chance that it will stall or take the NE curve while over water. Anyone to the right of the storm can be at risk. So anyone from Tampa around to Pensacola/Perdido Key needs to be included in advisories.

For the official answer, you probably ought to e-mail NHC/TPC and get their take (if they have one).

Steve