Consider the following excerpt from a literary essay:
"In the poem, the author invokes the imagery of a storm brewing in the distance, a metaphor for impending change and uncertainty in one's life. This technique serves not only to paint a vivid picture but also to convey the emotional turbulence that accompanies transformation. Through the careful use of personification, the storm seems to growl with foreboding, establishing a relationship between nature and human emotion. Understanding these figurative elements is essential for uncovering the deeper meanings within the text."
Which of the following figurative language techniques does the author primarily employ to enhance the meaning of the storm as a metaphor for change?