OH, How I would love a new quest.. Dusty once said in some other thread, Weather systems are easy to implement but hard to give purpose for, Of around that in another thread.
Personally, Not sure why what he means by purpose but I'd imagine a graal weather system would obviously have the purpose of making graal much more beautiful, didn't like it? There is a weather option in your settings that already doesn't stop much weather as is. Other than maybe rain in someone's house. Not much past that.