After seeing the damage that Irma did to the keys first hand, I'd never take a hurricane warning with a grain of salt anymore. I left the Keys last year the day that the mandatory evacuation was ordered just since that is when my flight was going out, and then I was there this past July and the beach we like to hang out is completely changed. They still don't have some of the buildings built back up, playgrounds, etc. There is still a bunch of places you drive by and just see the damage still.
If the flight paths today from flightaware are a sign of how they will fly tomorrow, it looks like my BWI to FLL flight is most likely going to be on. I'm still crossing my fingers though.
https://flightaware.com/live/flight/SWA1914/history/20180914/1205Z/KBWI/KFLL