Regional and Seasonal Characteristics of Tornado Debris Signatures Associated with Significant Tornadoes from 2010-2017 (350)

Steven Nelson, National Weather Service, , GA

Adam Baker, National Weather Service



The tornado debris signature (TDS) is a strongly correlated area in space and time of relatively high reflectivity, a strong velocity couplet and low correlation coefficient, and has been shown to strongly correlate with debris lofted by a tornado and with observed tornado damage tracks.

This study will present overall trends and regional and seasonal differences of the TDS observed from WSR-88D dual-polarimetric radars across the Continental U.S. from May 2010 to December 2016. Specifically, the prevalence of a TDS, the maximum height and width of a TDS, and the minimum correlation coefficient of a TDS were compared with observed wind speed estimates obtained from NWS damage surveys. These results were then stratified into subgroups of different large-scale vegetation areas of the country and during the different periods of the year, corresponding to different stages of deciduous trees and agriculture growth. For instance, between the abscission process when deciduous trees lose their leaves and the dormant stage, leaves may more easily become lofted during a tornado and thus, more easily detected by weather radar. Finally, the land type from the Department of Interior's and U.S. Geological Survey's National Land Cover Database was obtained for the path of each tornado. Correlations with TDS characteristics were also made with the predominant land type(s) along the tornado path.