Well, I think snow may be possible for rally races. Personally, I'd love to rally in the snow. Maybe if Smokey Mountain was covered up in snow, I'd take the very agile Peugeot 206 WRC and kick some snow up. Maybe you can be my co-driver, Miss McLaren. If you ask me, rain is not real easy. The objective is to try to make the rain not sacrifice frame rate and slow down racing. "Pro Race Driver" had cheap rain effects, but had rooster tails of water. I don't think I've ever seen glossy roads with car reflections in real life, so that can be negated. As far as changing weather conditions go, it can be real easy or real tough. It's like frying Eggo waffles- you fry them just right, or altogether wrong.
Here in Houston, TX, USA as usual, getting rain here this morning. It's likely the bad weather will continue for the next few days. So if you want to talk weather, a lot of testing and sampling will have to be done to make it work to perfection. Until then, farewell until next time. "Pika-pikachu!" McLaren, is this your Pikachu? Here you go.