We have been tracking a persistent supercell near Simla, CO for the past couple hours.   The lower left panel shows a seven sigma lighting increase, followed by a three sigma increase preceded the eventual tornado development by around 15 to 17 minutes.  It is thought the vertical stretching of the updraft into in the mid levels as indicated by a significant increase in lightning eventually may have manifest in the lower levels by eventual development of a tornado.

John Pendergrast