In this mod, Dynamic Weather 0.9.4 (Panoramic Mod Textures) is the default weather system that the weather is totaly dynamic (as seen in the video shown below). In the mod optionals\extras folder, there is a mini-mod that reduces the probablity of rainy\stormy weather of the DW 0.9.4.
Dynamic Weather 0.9.4 with Panoramic Mod Textures:
There is another Weather System that you can install in this mod, Stalker Weather Overhaul (See the video below this text, the download link of SWO is in this moddb page) wich is also a kind of Dynamic Weather.
Salker Weather Overhaul 3.1.1: