NSSL tornado climatology expert, Harold Brooks has written a blog post about the remarkable absence of tornado activity during the 12-month period from May 2012 to April 2013. The estimated number of EF-1 or stronger tornadoes for this period is 197, a record low.
Brooks compared the current 12-month period with previous (E)F1 or stronger tornado counts back through 1954. He found the previous low for (E)F1 and stronger tornadoes in a 12 consecutive calendar month period was 247, from June 1991-May 1992.
This apparent record was set less than two years after the record for most EF1+ tornadoes in a 12-month period was set, with 1050 from June 2010-May 2011.
Read the full post here: U.S. Severe Weather Blog.