A large group of ignorant people convinced something terrible is soon to happen, who all then act in a panic to prepare for this ominous event, after which the event fizzles, falls short of the dire expectations, or completely fails to occur
Did you see all those people stripping the Wal-Mart shelves in NYC before Irene arrived? A real nurricane, that was.
The act of telling one's fellow movie-goers what's happening in the movie they've already seen. One is narrating (speeking aloud) during a movie, telling fellow movie goers what's happening, or the direction (navigating) - put both words together and you have one of the most annoying behaviors known to the thinking man: narrigating!