yes, to some degree...
I have some mods here that mess with the weather:
specifically, anything beginning with "
PunishingWeather-". If you look in the XML you can see all the parameters to change. My "Core" mod makes it rather nasty and nasty looking, and the other "override" or "additional" mods just make the weather worse. If there's something you would like, and I can accommodate it, I could make another mod and tweak the weather further (maybe, no promises).
The Jawoodle fog I *believe* is from a modder called Donovan, and it is called "NightFog", which is here:
https://github.com/donovan522/donovan-7d2d-modlets/tree/stable/donovan-nightfog
HOWEVER its fog only for the night, so to get JaWoodles day fog you'll have to tweak the modlet (its a 1 line modlet). I'm guessing JaWoodle/Donovan hand coded mods for him, or he used the console debug to set the fog...
Additionally: You can alter weather in the debug menu of the game. I mention this because the fog from the debug menu is MUCH more dense and you can change the fog color, which cannot be done via XML mod that I know of (because I want to do that and I cannot).
Additionally: From the Dev forums, it appears weather may get a makeover in a20, so maybe my mods (and fog color changing via XML) will be different in a20. Hopefully it will be more awesome and configurable via XML modding.