Washington Post : “It may be the case that more tornadoes are being noticed today”

There is no clear indication that severe thunderstorms and tornadoes have become more common due to climate change, in part because of major limitations in relying on the historical record of severe weather reports. While the number of tornadoes recorded in the U.S. has just about doubled during the past 50 years, the number of strong tornadoes (EF2 and above) has actually been decreasing. It may be the case that more tornadoes are being noticed today, given a network of trained storm spotters and a national Doppler radar network, both of which didn’t exist as recently as the early 1980s.

http://www.washingtonpost.com/