I'm a game developer and owner of Reflective Layer, an independent game studio in Philadelphia. We started out as indie film maker but then in 2007 switched to indie games. Our current project is Prague. It's a RTS/ village building game featuring a computer simulated weather system which generates wind, rain, snow and other metrological conditions. These conditions impact gameplay in every aspect.
Here are few screenshots of our upcoming game Prague. These shots show some of the daylight and weather effects that we're adding to Prague.