Honestly, if anyone you knows is faced with leaving or staying when a category 4 (almost 5) hurricane is bearing down on your home, simply take this video to them and show them what they are in for.
This footage is from storm chaser Brett Adair. Brett and his partner were driving around Mexico Beach, Florida when the storm began to roar. They sought a protective area for their vehicle, and higher ground for them. Once they left their vehicle, the footage just got worse as the the storm surge poured in.
If you don't have time, skip the the 30-minute mark when their panic sets in.
Some language is NSFW.