It's Personification. This figure of speech gives animals, ideas, or objects human qualities. These qualities can include emotions, guestures, the ability to talk, desires, and sensations. In this sentence, the storm is a state which distrubs the environment.
It is not a human, but the sentence alludes to the storm sleeping for two days, which is a trait that humans have. Obviously a storm doesn't have the ability to close their eyes and go to sleep, but humans can, which is why this sentence is an example of personification. Another example of personification is "The stars danced the night away".