Despite advancements in our understanding of supercell thunderstorms, numerous questions remain regarding relationships between their environment, storm-scale characteristics, and tornado potential. In particular, quantifying the range of storms possible in a given environment is an active area of research, and examining these relationships in time remains even more unexplored. This dissertation addresses these two research foci using a blend of numerical modelling and observational analysis.

First, two 15-member ensembles of high-resolution, idealized simulations are con- ducted to explore the sensitivity of supercellular tornado production to small, storm-scale variations. The composite near- and far-field tornadic VORTEX2 profiles (Parker 2014) are used as the base-state for each of these two ensembles. Within each environment, the initial wind profile is perturbed slightly, resulting in 15 slightly different storms evolving within each environment. Based on my definition of a “tornado” in the simulation, all members in the near-field environment produce a tornado while only 40% of those in the far-field environment produce a tornado. Important storm-scale characteristics differ between the two ensembles, especially in terms of low-level updraft strength and surface outflow temperature. These results also show that storm-environment modifications can result in a local environment much more supportive of tornado potential.

Next, an observational dataset consisting of 902 soundings and 220 supercell tracks is analyzed to better understand storm-track characteristics, particularly related to the right turn, and their relationship to environmental conditions. No significant correlations were found between the environmental parameters examined here and the time of the right turn. However, larger values of 0–1 km AGL streamwise horizontal vorticity magnitude tended to coincide with cells turning right within the first 65 minutes of their lifetime, and vice versa for smaller values of streamwise horizontal vorticity. The mean time between the cell’s first appearance on radar and the right turn was around 45 minutes for all supercells with a standard deviation of 25–30 minutes. Mean streamwise horizontal vorticity was significantly larger in the tornadic environments in the 0–1 and 0–3 km AGL layers, but not the 0–0.5 km AGL layer. Interestingly, mean crosswise horizontal vorticity was not significantly different between the tornadic and nontornadic subsets.

A goal of this work was to identify relationships and/or processes linking environ- mental conditions to supercell characteristics that may be relevant to real-time forecasters, either immediately or in the near-future. Some conclusions from this work that are relevant to this goal include further quantifying what range of storms, in terms of tornado production, are possible in different environments and mean statistics regarding characteristics of the right turn in supercells. Future work will continue to use a blend of analysis methods to further examine supercell environments, storm-scale characteristics, and tornado potential in ways that will most efficiently benefit operational forecasting, emergency management, and other audiences.