This is a rapidly conceived and executed shot, as a big storm headed in from the Simmen valley from western Switzerland. I saw the distant clouds being illuminated by lightning (which accounts for the varied colouring in the clouds) so I grabbed a tripod and framed my shot from our living room window, setting exposure and taking a couple of test shots. I was pretty happy with the shot as it was, particularly with the streelight area giving some foreground interest, but the picture was a bit heavy in the lower part of the frame. So, I grabbed a flashgun, set it to 1/4 power and fired it into the trees in the lower centre of the frame, filling in just enough light to bring a little detail into the image.
You can see a larger version of this photo in the Niesen gallery.