Lightning and Thunder (maybe earthquakes)
Extract this file (game.wac) to the comanche 4 folder.
Then run c4.exe /d
Game.wac is a script to trigger advanced events, music, sounds lightning thunder etc. Its global and affects all maps when the file is loaded.
Here is just a glimps of what can be done with these wac scripts.
This is continious sample so you will probably want to modify it to occur randomly. Edit with notepad. The info on wac scripts can be found in the game.wac from DFBHD.
You can also just name the script the same as the map to affect only that map.
enjoy!
Bane