Radar Studies of a VORTEX2 Tornadic Supercell: 7 June 2010

A tornadic supercell in the western Nebraska panhandle on 7 June 2010 was observed by four VORTEX2 mobile radars (the NOAA NOXP and three CSWR Doppler on Wheels (DOW5, DOW6, and DOW7)). Single- and multi-Doppler analyses from these radars are used to investigate the evolution of the supercell and the genesis of the tornado. The use of the over-determined dual-Doppler method in this study supports earlier findings that increasing the number of radars increases the area covered by wind vectors and improves the accuracy with which wind estimates may be obtained. The rapid development of the low-level mesocyclone and strong rear-flank gust front winds are observed to occur in the ten-minute period prior to tornadogenesis. The radar tornadic Delta-V (DV) velocity signature first appears slightly aloft just before tornadogenesis, after which the strongest tornadic DV signatures are seen at the lowest levels during the time of tornadic damage. The tornado, rated only EF-1, but with a 19-mile path length, exhibited several cycles of strengthening and weakening. Dual-polarization signatures for updraft, hail, the Zdr arc, and the tornadic debris signature (TDS) are all noted in this analysis. There is evidence of a Low Reflectivity Ribbon in the radar high-resolution polar plots, and its location best corresponds to gradients in Zdr.