The development of Tropical Cyclone Diana (1984) is simulated with a mesoscale model using a 1.2-km grid spacing over a regional-scale domain. From only synoptic-scale initial conditions, a warm core storm forms from a trough along a remnant frontal zone. The high-resolution simulation mirrors the three observed phases of development-- initial MCS eruption, convective quiescence, and convective redevelopment and tropical vortex emergence-- with individual convective cells organizing into bands and a tropical vortex forming. Parallel simlations using 3- and 9-km grid sizes are also performed to elucidate the sensitivity of storm formation and evolution with meshes implicating both quasi-resolved and parameterized convection. While all of the experiments reproduce the three phases of development, the structures of the 3- and 1.2-km runs exhibit greater realism and are quite similar. The presentation will focus on the highest-resolution results, but will also address the cyclone's evolution from the perspective of averages of various storm development criteria.