Determine whether the swirl ratio predicts tornado structure and behavior

Determine whether the swirl ratio can serve as a predictive parameter for distinguishing or forecasting single-vortex and multiple-vortex tornado behavior in real, non-stationary tornadoes.

Background

The paper discusses the swirl ratio as a parameter commonly used in laboratory vortex experiments and compares its values across the simplest, refined, and full tornado models. However, the authors emphasize that the parameter does not by itself guarantee the presence of a single or multiple vortex and may be too vague for real, non-stationary tornadoes.

The unresolved question is whether ongoing efforts to define and apply the swirl ratio more rigorously will establish a reliable predictive relationship between the ratio and tornado structure or evolution.