What metaphors are used in Isaac's Storm: A Man, a Time, and the Deadliest Hurricane in History by Erik Larson?

The barometers throughout the novel play an important role in weather tracking. Each of them records atmospheric pressure, but they are also the best warning signals that a catastrophic weather event is about to occur. In the middle of the hurricane, John Blagden records the then-lowest barometric pressure to date. It becomes a metaphor for the array of human emotions when under threat.