REX: Real Environment Xtreme
Of course you're aware that the flight sim community takes things rather seriously. Where modding is concerned, they build planes like they're actually building planes. The manual for one of these suckers is bigger than the manual for my car; in fact, the 2005 Honda Jazz feels less realistic all round. Meanwhile, when these modders are building the weather, they do it better than God. His clouds have been rubbish for years.
You'll get the lot if you invest the considerable time and money required by Flight Simulator X and its biggest mod, Real Environment Xtreme . The latest version is called REX Essential and is soon to be improved by REX Essential Overdrive. Assuming your mind can handle something so essentially overriding, what that gives you is almost 10gb of clouds, runways, dawns, dusks, reefs, waves... an awful lot of photorealistic stuff .
The way the mod works is to build a weather profile for the particular flight you add to your planner. It takes a while to import the necessary textures and runs a background app to keep track of them, but it's well worth the rigmarole. Add it to things like TileProxy and a high-fidelity terrain mesh and you have a game that makes Microsoft Flight look like... well, Microsoft Flight.
