This is the oldest known photo of a tornado. It was taken on August 28, 1884 near Howard, South Dakota. The name of the photographer is not known. From thw N.W.S.

NOAA Home Page - Tornadoes Portal

Enhanced F Scale for Tornado Damage

An update to the the original F-scale by a team of meteorologists and wind engineers, to be implemented in the U.S. on 1 February 2007.