I've been trying to come to an answer for what conditions need to be in place to allow for the formation of a permanent or at least a long lasting weather pattern, in this case a large storm. I would like to establish that a certain area of a planet I am working on has a large storm that has been there since at least as long as the planet has been known.
For starters, it would likely have to form over a tropical area of the planet, allowing the waters heat and the air pressure to bring the proto hurricane to form and wind conditions just right to not collapse it. Once the pressure near the enter drops and storm starts spinning. Once it picks up in speed it begins to move, but how could that naturally be stopped? If it moved over land, what would need to happen to keep it alive.
In short scientifically for a large permanent storm to form and exist what conditions need to be in place and if impossible, what can be handwaved to allow it.