The title 'the day it rained forever short story' gives an impression of a long - drawn - out situation. It could be that the rain is a backdrop against which the real story unfolds. Perhaps the story is about how people cope with an unexpected and never - ending event. The rain could also be a way to set a mood of mystery, as if something strange is happening on this day that the rain just won't stop.
I haven't actually read this short story specifically. But generally, a story with such a title might be about a day where the rain is a central element. It could symbolize a sense of melancholy or change. Maybe the rain is a metaphor for the characters' emotions that seem to go on and on, just like the rain that never stops in the story.
In 'the day it rained forever short story', the perpetual rain could be used to create an atmosphere of isolation. The characters might be trapped, not just physically by the rain but also emotionally. For example, if it's a story about a relationship, the rain could represent the problems that keep coming and won't go away, just like the unending rain.