Im leaving Sept 2nd as well! Were going Sept 2nd to 9th!
I think the weather will be fine. Ernesto will be long gone by that time and it should be your typical Florida weather. Im going in with the expectations of it being pretty hot with some afternoon showers. The only thing that will make my trip less enjoyable is if there is no sunshine. I'd rather have sunshine and sweat, than walk around in a gloomy, humid park.