Additional Evaluation of the Spatiotemporal Evolution of Rotation during Tornadogenesis Using Rapid-Scan Mobile Radar Observations

Abstract This study builds upon recent rapid-scan radar observations of mesocyclonic tornadogenesis in supercells by investigating the formation seven tornadoes (four from a single cyclic supercell), most which include samples at heights < 100 m above level. The spatiotemporal evolution tornadic vortex signatures (TVSs), maximum velocity differentials across couplet, and pseudovorticity are analyzed. In general, formed following non-descending pattern evolution, although one case was descending over time scales O (<60) s another dependent criteria used to define tornado, may have been associated with rapidly occurring top-down process. Thus, it determined that vertical sense tornado can be sensitive employed TVS. Furthermore, multiple instances were found TVSs terminated below 1.5 km, sampling this height often limited. Significance Statement It is generally well understood form short [i.e., (∼60) s]. Despite fact, detailed scientific measurements during just prior genesis remains limited, particularly very near ground on space sufficient observe processes. Multiple studies supported rotation supercell tornadoes, but small number analyzed cases still insufficient for generalization. investigates new using high resolution data near-ground level examine height. For observable platform (∼30) s], occurred predominately manner five out studied, while two criterion “tornadic” signature.