Updated 2 May 2013 to correct typo on date of previous low tornado countThe 12-month period from May 2012 to April 2013 was remarkable for the absence of tornado activity and tornado impacts in the United States.We can start by looking at the number of EF1 and stronger tornadoes during that period. A final count is available through January 2013 and we have a pretty good estimate of how many occurred in February through April, although final numbers won’t be available until July. Although the 12 month total may change a little bit with the final data, it’s unlikely to...