Impact of the initial convective arrangement on simulated MCS development

Mesoscale convective systems (MCSs) that develop from linearly-arranged convection at initiation have been observed to evolve toward larger, longer-lived, more severe, and rainier systems than MCSs that develop from scattered convection at initiation. To examine and better understand this observation, the Regional Atmospheric Modeling System (RAMS) is used to investigate the sensitivity of MCS development to the initial convective ensemble structure. Several idealized simulations of MCS development are performed that only differ in the initial arrangement of convection, as imposed by the strategic placement of warm, moist bubbles. The simulated MCSs that develop appear qualitatively similar to one another regardless of the convective arrangement at initiation; however, some significant quantitative differences exist among the systems in terms of size, duration, and total precipitation. Further analysis reveals that the interaction between the storm-generated cold pools and the ambient low-level vertical wind shear strongly influences the differences that develop among these systems.