1053 The Benefits of Terminal Doppler Weather Radars for Tornado Detection and Warning: Comparing Radar Signatures from TDWRs with Those from the WSR-88D

Wednesday, 10 January 2018
Exhibit Hall 3 (ACC) (Austin, Texas)
Daniel Reilly, NWS, Dickinson, TX; and J. Evans

In this study we will look at cases of tornadogenesis in Southeast Texas as viewed from the National Weather Service (NWS) Weather Surveillance Radar 1988 Doppler (WSR-88D) and the Federal Aviation Administration’s (FAA) Terminal Doppler Weather Radars (TDWR) located at Bush and Hobby airports in Houston. Radar signatures identified in the base reflectivity and base velocity fields will be compared with a focus on signatures that aid the tornado warning decision process. The strengths and weaknesses of each radar for tornado detection will be shown from three recent tornado events.

It was found that the TDWRs, which have lower and more frequent lowest elevation scans and higher spatial resolution due to their narrower beamwidth, often provided important details on storm structure that were not evident in data from the WSR-88D. In one dramatic case, the WSR-88D showed an HP supercell with a strong, broad rotation while the TDWR showed fine-scale vortices pivoting around the larger-scale mesocyclone. Based on post event damage surveys and witness reports, the location of these fine-scale vortices matched at least two areas of significant tornado damage (EF1 and EF2). In the other cases, important radar signatures (hook echoes, debris balls) were evident in the TDWR reflectivity data but not with the WSR-88D. These cases demonstrate the benefit of including TDWR information in thunderstorm monitoring and warning decision making.

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