This is a timelapse of a Colorado supercell from June 2nd, 2012.
The supercell emerges from the darkness about halfway through and you can really see how it flies across the horizon, and the rotation and strong updrafts.
A few notes...when I'm stormchasing I'm usually in a hurry and the one thing I always forget to put into manual mode is white balance. I tend to stick to AWB when I'm just randomly shooting outdoors, so that's the one thing I always forget about.
When timelapsing, always get your white balance in manual mode, preferably some K value that looks good to you.