One way to generate scenario ideas for short stories is to mix different genres. Combine elements of science fiction and mystery. For example, a spaceship disappears without a trace, and a detective has to solve the mystery using futuristic technology. Also, you can draw inspiration from nature. A forest that has a strange, magical energy could be the setting for a story. Maybe the trees can communicate with the protagonist. Another tip is to think about emotions. A story about a character who is consumed by jealousy and how it drives them to do extreme things can make for an interesting short story scenario.