Accurate simulation of mesoscale gravity waves (MGWs) and their interactions with precipitation systems remains a considerable yet critical modeling challenge, owing to sensitivities to small-scale, nonlinear processes. This study analyzes a unique and complex MGW event that impacted the south-central and mid-south United States over a 16-hour period on 7 March 2008, spanning Texas to Kentucky. The event was distinguished by the co-occurrence of two MGW forms: a long-lived wave of depression in a dry environment, marked by subsidence, adiabatic warming, and drying; and a short-lived wave of elevation (MGWEL) in a moist environment, associated with rising motion, moist adiabatic cooling, and an embedded rainband. Despite similar synoptic backdrops (jet-streak coupling and a pre-existing baroclinic zone), the waves diverged in structure and energetics once deep convection initiated, underscoring strong sensitivities to microphysical and boundary-layer processes. The transition from a dry to moist wave regime posed a substantial modeling challenge. High-resolution simulations using the Advanced Research WRF (ARW-WRF) model reveal key insights into this transition, including wave maintenance processes and sensitivity to microphysical parameterizations.The results have implications for improving forecasts of high-impact mesoscale disturbances in environments where dry and moist processes interact synergistically.