caa a22 4500 605470987 CHVBK 20210128100330.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00382-014-2277-3 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2277-3 The increasing efficiency of tornado days in the United States [Elektronische Daten] [James Elsner, Svetoslava Elsner, Thomas Jagger] The authors analyze the historical record of tornado reports in the United States and find evidence for changes in tornado climatology possibly related to global warming. They do this by examining the annual number of days with many tornadoes and the ratio of these days to days with at least one tornado and by examining the annual proportion of tornadoes occurring on days with many tornadoes. Additional evidence of a changing tornado climate is presented by considering tornadoes in geographic clusters and by analyzing the density of tornadoes within the clusters. There is a consistent decrease in the number of days with at least one tornado at the same time as an increase in the number of days with many tornadoes. These changes are interpreted as an increasing proportion of tornadoes occurring on days with many tornadoes. Coincident with these temporal changes are increases in tornado density as defined by the number of tornadoes per area. Trends are insensitive to the begin year of the analysis. The bottom line is that the risk of big tornado days featuring densely concentrated tornado outbreaks is on the rise. The results are broadly consistent with numerical modeling studies that project increases in convective energy within the tornado environment. Springer-Verlag Berlin Heidelberg, 2014 Tornado nationallicence Trends nationallicence Cluster nationallicence Outbreak nationallicence Efficiency nationallicence Elsner James Florida State University, Tallahassee, FL, USA aut Elsner Svetoslava Florida State University, Tallahassee, FL, USA aut Jagger Thomas Florida State University, Tallahassee, FL, USA aut Climate Dynamics Springer Berlin Heidelberg 45/3-4(2015-08-01), 651-659 0930-7575 45:3-4<651 2015 45 382 https://doi.org/10.1007/s00382-014-2277-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2277-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Elsner James Florida State University, Tallahassee, FL, USA aut NATIONALLICENCE 700 1- Elsner Svetoslava Florida State University, Tallahassee, FL, USA aut NATIONALLICENCE 700 1- Jagger Thomas Florida State University, Tallahassee, FL, USA aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/3-4(2015-08-01), 651-659 0930-7575 45:3-4<651 2015 45 382