This picture is a single exposure.   I achieved the look by holding the shutter open (during a hand-held exposure) -  for about a minute in duration.   The ambient darkness left little imprint; however, every flash of lightening stamped some element on the digital plain.  I deliberately moved the camera around after individual flashes to create the sense of a kinetic strobe.... which, given the wind and wail and rain, is exactly what was going on.