NWC REU 2017
May 22 - July 28



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Dual-Wavelength Polarimetric Radar Analysis of the May 20th 2013 Moore, OK, Tornado

Alexandra Borunda, Casey Griffin, and David Bodine


What is already known:

  • Tornadic debris signatures can confirm the presence of a tornado and provides information about the amount of damage occurring.
  • Debris scattering characteristics were found to be different at S- and C- band.

What this study adds:

  • Observational confirmation of differences in the debris scattering characteristics between S- and X- band polarimetric radar observations.
  • The first time S- and X- band tornadic debris signatures have been compared, providing others an opportunity to compare our results with previous S- and C- band studies.
  • A better understanding of the observed scattering characteristics of tornadic debris signatures between S- and X- band is obtained from a violent tornado that lofts an abundance of debris.


The 20 May 2013 Moore, Oklahoma, Tornado was rated as an EF-5 on the Enhanced Fujita scale. Its destructive display of power claimed the lives of 24 people that laid in its path as well as further impacting the local population with damaging winds, large hail and billions of dollars in damage. Because of the tornado’s close proximity to multiple radars in the Oklahoma City metro, it provides an opportunity to better understand the scattering characteristics and the dynamics of tornadic debris signatures at different wavelengths. The two radars compared in this research are the PX-1000 that operates at X-band and the KCRI radar that operates at S-band. By comparing the S -and X-band with histograms, box and whisker plots and plan position indicators (PPI) differences in scattering can be seen. While comparing reflectivity, it is seen that S-band is higher than X-band. S-band exhibits more negative values of differential reflectivity as well as lower and more variable values of correlation coefficient.

Full Paper [PDF]