Tornado Debris Signatures Associated with Hurricane Harvey's Tornadoes in Southeast Texas

In addition to widespread record flooding, Hurricane Harvey (2017) produced 23 tornadoes in the NWS Houston/Galveston warning area from 12 UTC 25 August, 2017 to 12 UTC 28 August, 2017. Of the 23 tornadoes, 17 produced EF-0 damage on the Enhanced Fujita Scale and 6 tornadoes produced EF-1 damage. Since tropical cyclone (TC) tornadoes are short lived and weak (generally EF-0 to EF-1 damage), documenting these cases helps forecasters in the warning decision process. This study documents a total of 6 Tornado Debris Signatures (TDS) associated with the TC supercells that produced tornadoes, similar to the study performed in Edwards and Picca (2016). Documenting these 6 TC TDS cases would add to an already small set of TC TDS cases (36) from 2010 to 2016 determined in Edwards and Picca (2016). Finally, this study compares rotational velocities and echo tops of the 6 TDS tornado events to the 17 other tornado events, showing how the TC supercells producing the TDS tornadoes are more substantial than those without a TDS. Archived radar data from the KHGX WSR-88D is analyzed using Gibson Ridge GRAE2 software to determine TDSs, calculate TDS heights, calculate associated rotational velocities, echo top, and also determine how long the TDS signature persisted. This work is part of a larger study to understand differences between the characteristics of tornadic and non-tornadic TC convective cells and their environments. The end goal of the study is to improve tornado warning skill and reduce the False Alarm Ratio (FAR) through more efficient interrogation of potentially tornadic cells.