i did a recording of a thunderstorm from my front porch a few summers ago. i set up a pair of MXL 603's, spaced about 20ft apart (one on each end of the porch). i live out in the country, so it's easy for me to get a good recording.
the stereo effect is VERY cool--especially on cars passing by and thunder cracking from left to right, etc. a little unrealistic in the ultra-wide doppler effect, but still quite cool.
unfortunately, b/c i was recording with an m-audio mobilepre at the time (which has no inserts) straight to computer via USB, the really loud thunderclaps clipped the inputs and i've got some clipping in a couple very prominent spots. my kingdom for having had a limiter in the chain.
but otherwise, it was a very easy recording to make. you just have to get out there before the storm starts so you can get it all. i'm going to record another one this summer, probably with an array of mics.
the crickets that kicked in when the storm was over was ultracool.
cheers,
wade