i know there is lightning in the stock game, you just have to have the right weather situation.
i cant say about with added mods that change the environmoent thou but try the mission i include with my smaller rain mod and dont use any environmental mods. it has a bad weather mission i created so you get to see the change in rain size and many people report seeing lightning in it.
that mission doesnt do anything thou and there is no mission to do but you will see lightning
