Cloud response to lateral interactions from convective strength-variable neighbors

The organization of convective clouds plays a key role in convective system development, yet the interactions between neighboring cloud entities remain unclear. This study examines how clouds of varying convective strength influence spatial and temporal evolution of their neighbors by idealized large-eddy simulations. Results reveal that interactions predominantly occur during the late mature stage of the cloud lifecycle, where neighboring clouds suppress liquid water path and vertical development while enhancing horizontal expansion, leading to a net reduction in cloud volume. Thermodynamic and dynamic analyses indicate that warming and moistening from neighboring clouds promote low-level convergence and updrafts on their adjacent flanks, driving horizontal growth but inhibiting vertical extension by shifting the cloud core toward neighboring clouds. The study underscores the importance of lateral interactions in shaping the organization of shallow convective cloud systems and provides insights for improving cumulus parameterization in models.