Amanda Murphy - April 29

Name:     Amanda Murphy

Title:    Mesocyclone Vertical Alignment in Tornadic and Non-Tornadic Supercells: A Case Study

Location: Zoom

Date:     2020/04/29

Time:     03:00 PM

Series:   Weather and Climate Systems

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https://oklahoma.zoom.us/j/505651584

Zoom Password: 996546

Abstract: Recent studies have examined the vertical alignment of the mesocyclone in tornadic and non-tornadic supercells. Homeyer et al. (in prep) examined 478 non-tornadic and 294 tornadic supercells using probability-matched composite means of NEXRAD WSR-88D data and found that, compared to non-tornadic storms, the mesocyclone in tornadic storms was much more vertically aligned. This study examines two supercells that initiated within the same environment, to the northwest of the KFDR radar in southwest Oklahoma, to determine if these composite mean results are repeatable in two close-proximity supercells. These supercells, dubbed the Corn and Hennessey supercells by Britt (2018), followed similar tracks but only the Corn storm produced a tornado. Herein we examine the vertical alignment of the mesocyclone, using azimuthal shear calculated from the KFDR radar binning into low- (0.5-3 km), mid- (4-7 km), and upper-level (≥ 8 km) layers. Preliminary results show the mid- and low-le
vel mesocyclone was less vertically aligned in the Hennessey (non-tornadic) storm than the Corn (tornadic) storm. Results also show that the mid- and low-level mesocyclones were well aligned before and during the single tornado produced by the Corn storm, but lost vertical alignment after the tornado ended.