An Update on Tornado Trends Across the U.S.

Tornado frequency has changed greatly across the much of the United States since the 1990s. Much of this is due to increased awareness of tornadoes through the activation of large spotter networks, the installation of Doppler radar and the modernization of the National Weather Service.

The NOAA Storm Prediction Center maintains the database for annual tornadoes derived from the original Storm Data reports. Storm Data is comprised of tornado segments presently defined as individual counties crossed by a particular tornado path. SPC takes these tornado segments and derives the individual tornado tracks to derive the actual number of tornadoes annually.

This presentation will update the tornado trends since the onset of the 21st Century and compare it to the later half of the last century. A Climatological trend will also be presented. This is a valuable tool to estimate the status each year of where the United States is annually on tornadoes and other severe weather events.