This mod replaces all the natural Bone County textures, such as dirt, sand, tracks, rock, cliffs, and such, with snow. It looks simply amazing. I reccommend using the fog cheat for optimum effect, gives it a snow storm appearance. I used the snow texture from the LC cutscene, from the St. Marks Bistro so it looks as good as snow will ever look in SA.
The solution to editing weather is in the effects.fxp. There's only one app for that file, and it doesn't really help much.
-It's in German
-No search function
But I will work on editing many aspects of the weather. I'm not sure if it's possible to edit sand/rain textures, that's probably sorta hardcoded. I'll give it a go, can't make any promises though.
Well, searched through the whole thing. Didn't find any rain data. But I will tweak some lines of code, and some textures, see what works. I edited the sandstorm, but the actual sand that blows is very transparent, so it wouldn't really help to screw with that. But as I said will tweak with this, see what I can do.