JASEN GRECO. Idealized Simulations of Supercell Thunderstorms Interacting with Stationary Boundaries (Under the direction of DR. CASEY DAVENPORT) Stationary frontal boundaries have a considerable impact on the weather within their vicinity. The enhanced horizontal vorticity seen at these boundaries can aid in the development and intensification of severe weather, especially supercell thunderstorms. A supercell’s mesocyclone is known to be enhanced near boundaries, as proximity helps to strengthen the storm and increase the changes for tornado production. However, stationary boundaries are also associated with strong spatial gradients in environmental quantities (e.g., instability, vertical wind shear, and helicity) that are known to influence storm intensity and longevity; thus, these temporal and spatial variations in the environment can also significantly influence supercell evolution. It is unclear which is more influential on supercell intensity and evolution: the attendant boundary circulation or the rapid changes in the near-storm environment. Thus, the research presented herein aims to explore the impact of rapidly changing background environments in idealized simulations without an accompanying boundary circulation. The base-state environment tested in the model was based on a real-world supercell-stationary boundary interaction event from 29 May 29 2011. Representative environments were generated from RUC model analyses at near-storm inflow locations on the warm-side of the boundary, on the cold-side of the boundary, and at the boundary itself. Idealized model experiments in CM1 tested each of these environments either fixed over time (control simulations), or varying over time via base-state substitution (BSS). In the BSS experiments, the background environment either transitioned from warm-to-cold or cold-to-warm environments; the amount of time spent in either the warm-side, cold-side, or boundary environment was varied in 15 min increments to mimic different angles of approach for a supercell to interact with a boundary, impacting the "dwell time" on the boundary itself. While the results from the transition from the warm-to-cold environment were not informative about the study goal due to the generation of widespread convection, the results from the transition from the cold-to-warm environment revealed that, contrary to observational studies, longer dwell time in the boundary environment led to less organization and dissipation of the supercell. Dissipation is suspected to have occurred due to the increasingly warm and dry mid-level in the boundary environment, which likely enhanced entrainment and supported eventual dissipation of the supercell. However, the generalizability of this result should be explored with additional research. Future work includes a deeper analysis of the main aspects of this study, such as including more representative supercell/boundary interaction events, analyzing the metrics of the supercells themselves, and addressing the development of widespread convection in the warm-to-cold simulations.