This session is focused on the development and evaluation of aerosol cloud interactions in large-scale (regional and global) models. Large-scale models of weather and climate continue to advance their representations of aerosols, and the interactions between aerosols and cloud microphysics. There remain large uncertainties and discrepancies between observational based estimates of climate-scale aerosol-cloud interaction effects and the same effects estimated from global models. This uncertainty contributes to uncertainty in radiative forcing of climate, and in uncertainty regarding aerosol effects on precipitation. We invite papers on the development, evaluation, and analysis of Aerosol-Cloud-Interactions in large-scale models and intercomparison and coordinated modeling experiments that shed light on these issues. We encourage analysis of observational constraints on aerosol-cloud interactions and comparisons to models, both radiative effects and effects on precipitation in large-scale models. We also encourage process based studies using cloud resolving and other models that seek to bridge the scale gap between observations, detailed and large scale models.