AtmosFear is a mod for S.T.A.L.K.E.R. - Call Of Pripyat that tweaks and expands the vanilla weather system to be more realistic and various.
The new Absolute Texture pack is coming. This time with 5 different styles to choose from. Each area could have a different style applied so if you want Zaton to be rotten, Jupiter with dry autumny look and Pripyat completely dead at the same time, get Absolute Nature 2.
All that additional foliage and color creates a wonderful increased dimension of depth for the entire area. Love it.