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
Abstract:
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.