In this poetic example, rainfall and weeping are connected in a poetic explanation without presenting that image as a necessary physical cause. The figure centers on an imagined relation moderated by tentative expression.
Compare:
Assertive attribution: “The cloud weeps over the person’s absence.”
Attribution with doubt: “Perhaps the cloud weeps over the person’s absence.”
Both can create a delicate analogy; the second does not put forward the imagined cause as a firm claim.