I have experienced something similar in Montana, only seen one time. This was late into the night, during a severe thunderstorm. The storm woke me up. Looking out the window, lightning seemed to be continuous, for at least a couple of minutes. Like a xenon strobe light with the frequency sufficiently high to appear persistent to the human visual system. It looked like an alien abduction scene -- the outside landscape appeared to be illuminated as brightly as daylight.