While attempting to get closer to the storm, I was taking 15 second exposures of the lightning and hoping I could get something I could use. This is my best one...
The lightning acted as a flash...it only illuminated the outside during the brief lightning strike (that's why the clouds are not blurry). The lights, on the other hand, were bright enough to register on film/the sensor during the whole exposure, and that's why you see them 'streaming'.