Simulated ZDR Arcs and Tornadogenesis: A Preliminary Study

It is hypothesized that ZDR arc will increase in intensity and area ahead of increasing low level rotation (a proxy for tornadogenesis). To test this hypothesis in an idealized framework, synthetic ZDR arcs are generated by applying a polarimetric emulator to Cloud Model 1 (CM1) simulations of 15 tornadic and 15 non-tornadic supercells. The CM1 simulations utilize multi-moment microphysics, and the pertinent variables are used to generate the synthetic ZDR arcs. Both ZDR arcs and areas of low level rotation are objectively identified using an enhanced watershed object identification algorithm. Comparisons will be presented between the average ZDR value inside and outside of the arc, as well as the areal coverage of the arc and storm.