Date of Award

January 2023

Document Type


Degree Name

Master of Science (MS)


Atmospheric Sciences

First Advisor

Catherine Finley


The results of a large eddy simulation of a tornadic supercell featuring two distinct structures of streamwise vorticity in the forward flank downdraft (FFD) are presented. Each streamwise vorticity structure has a distinct effect on the low-level mesocyclone (LLM) strength and tornado strength. The two streamwise vorticity currents (SVCs) are associated with concentration and intensification of the LLM over the cold pool west of the tornado. The streamwise vorticity sheet (SVS) is associated with broadening and weakening of the LLM, primarily north of the tornado over the forward flank convergence boundary (FFCB). During each of these features the overall vorticity content of the forward flank was investigated using vertically integrated vorticity, and the low-level wind shear was explored using storm relative hodographs. The results illustrate the effect these streamwise vorticity structures have on the LLM, tornado, overall FFD vorticity content, and low-level wind shear in the FFD.