Research on tornado-like vortices reveals that the corner flow region exhibits the highest wind speeds, lowest pressure, and steepest velocity gradients, leading to the most catastrophic damage. Conventional analytical models derived from the Navier–Stokes or Euler equations often fail to adequately capture vortex–ground interaction, while empirical approaches typically rely on piecewise functions that result in discontinuous velocity fields. To address these limitations, this study develops a parameter-modulated model for single-celled tornado-like vortices, grounded in physical simulation measurements. Empirical formulas are established for the inflow boundary layer thickness, vortex core radius, maximum tangential velocity, and crossing-angle tangent, capturing their spatial variations and the near-surface intensification effect. By modulating an idealized inviscid framework with these height- and radius-dependent parameters, the model shows that the vortex core radius contracts and the maximum tangential velocity increases within the inflow layer and corner flow region, mathematically revealing the near-surface intensification mechanism driven by angular momentum conservation under the no-slip ground condition. Furthermore, the radially dependent boundary layer thickness elucidates the mechanism of corner flow collapse, while the modulation of the crossing-angle tangent yields a continuously differentiable, unified streamline topology transitioning from radial inflow to vertical updraft. Although the model intentionally departs from strict conservation laws within the inflow boundary layer and corner region, this represents a trade-off to prioritize realistic physics. Consequently, this work offers a closed-form, physically motivated, hybrid analytical–empirical tool for the analysis and prediction of destructive tornado wind fields.
Tian et al. (Mon,) studied this question.