No other mods, just your weatherpatcher. I didn't tick for random either.
I just left a customs raid, where it was bright and sunny, got dark, started to thunder and lightning, then slowly came back to sunny again... it seems it wants to rain and thunder, but this time your mod kept it under control.
I'm still so happy with your mod though. Love having the sunny days as it helps visibility for me.
I'm glad it somewhat works for you, shame it doesn't work as I hoped tho.
I do have a few things in mind that might make this happen less often, if I make something for this in the future are you willing to test it?