Characteristics of Simulated Tropical Cyclone Supercells
Open Access
- Author:
- Helock, Laura
- Graduate Program:
- Meteorology and Atmospheric Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- June 14, 2024
- Committee Members:
- John Peters, Thesis Advisor/Co-Advisor
Matthew Robert Kumjian, Committee Member
Paul Markowski, Program Head/Chair
Anthony Carl Didlake, Jr., Committee Member - Keywords:
- Tropical Cyclone
Tornado
Supercell
Hurricane
CM1 - Abstract:
- This study investigates the dynamical differences between simulated tornadic and non-tornadic tropical cyclone (TC) supercells using Cloud Model 1 (CM1). Grid point soundings from the Rapid Refresh (RAP) are examined in the vicinity of tornado-warned cells within TCs making landfall over the continental U.S. (CONUS) from 2013 to 2020. These soundings were averaged into two distinct input profiles: one for cells that were tornado-warned but did not produce a tornado (non-tornadic), and another for cells that generated EF2 or stronger tornadoes (tornadic). These refined soundings were input into CM1 to generate an ensemble of supercells for each identified scenario, perturbed by initial random noise. Compared to the non-tornadic simulations, the simulations based on the tornadic sounding had intense mesocyclones maximum vertical velocity near cloud base, along with wider overall updrafts. Because of the stronger low-level mesocyclones, simulated tornadic supercells produced more intense near-ground vorticity peaks. Hence, the dynamics that influence the tornado potential in Great Plains supercells are generally applicable to tropical cyclone supercells. TC environments have been shown to have relatively high RH relative to environments in the great plains, so humidity sensitivity simulations are done. Because of the wider updrafts found in the simulated tornadic TC supercells, they were more resilient to lower tropospheric RH, whereas the narrower updrafts found in the non-tornadic TC environments decayed when RH was reduced.