## 1. Introduction

This corrigendum concerns Figs. 3e,f, 5c, and 7e,f of Boyer and Dahl (2020), which show the integrals of the different terms contributing to the evolution of the horizontal vorticity magnitude. However, instead of showing the time integrals of Eq. (2) in the original paper as advertised, these figures show the magnitudes of the individual integrated terms of the horizontal vorticity vector equation [Eqs. (3) and (4) in the original paper]. This mistake does not affect the conclusions as discussed below, but we wish to clarify what was advertised, and what is actually shown in the figures. The difference is as follows.

## 2. Horizontal vorticity magnitude as advertised

*N*reflects the different terms in the vorticity equation (stretching and tilting terms, baroclinic vorticity production, etc.). Another way of writing Eq. (3) is

*α*is the angle between

_{N}

*ω**and*

_{h}## 3. Horizontal vorticity magnitude as shown in the figures

*ξ*,

*η*), such that

*ξ*,

_{N}*η*) being obtained by integrating the respective terms of the vorticity equations [Eqs. (3) and (4) in the original paper]. The total horizontal vorticity magnitude is given by

_{N}## 4. Ramifications

The focus of the paper was on the evolution of the vertical vorticity along parcel trajectories, especially on the observation that the vertical vorticity does not increase before the parcels enter the base of the vortex. Rather, vertical vorticity only increases after horizontal vorticity is abruptly tilted into the vertical in the corner-like flow. Although the origin of that horizontal vorticity is mentioned, the conclusions do not depend on whether, e.g., that vorticity originates from differential SGS mixing or from baroclinic production. The one claim regarding horizontal vorticity that was made based on the integrated budgets is that there is a significant positive contribution from horizontal stretching. This claim was supported by the fact that the individual combined tilting and stretching terms were large in magnitude and that the wind speed increased along the trajectories. Further support is provided by the recent analysis by Fischer and Dahl (2022), who also analyzed the evolution of the horizontal vorticity magnitude along trajectories entering tornado-like vorticies (TLVs), but they used Eq. (1). In their Figs. 4b and 11a, pertaining to mature TLVs, the stretching term indeed acts to increase the horizontal vorticity magnitude before the parcels enter the vortex.

We thus argue that our conclusions in the paper are unaffected by using a different equation than advertised to calculate the different terms contributing to the horizontal vorticity magnitude, but we wished to clarify the meaning of Eq. (2) in the original paper and to present the correct formulas that Figs. 3e,f, 5c, and 7e,f are based on.

## REFERENCES

Boyer, C., and J. M. L. Dahl, 2020: The mechanisms responsible for large near-surface surface vertical vorticity within supercellular and quasi-linear storm modes.

,*Mon. Wea. Rev.***148**, 4281–4297, https://doi.org/10.1175/MWR-D-20-0082.1.Fischer, J., and J. M. L. Dahl, 2022: Transition of near-ground vorticity dynamics during tornadogenesis.

,*J. Atmos. Sci.***79**, 467–483, https://doi.org/10.1175/JAS-D-21-0181.1.