Ok here goes. Im making a lvl where a storm rolls through with heavy wind rain and lightning crashing all around you. I've already received help with the wind part... But I need some help on how to do.

Lightning with sound & lighting. (I know how to do the effect but to get the lighting to flash and the sound to play at a specific moment of the burst is beyond me.)

I managed to create my own skybox but I still need some help on how to create dark moving clouds etc. Also for some strange reason my skybox isn't lined up...

How to create rain that changes directions as if the wind is blowing it one way at first then changes directions.

Thanks