Weather is chaotic, with strong sensitivity to initial conditions tied to the intrinsic limit to predictability. The strong sensitivity also suggests effective control in which small modifications to the atmospheric conditions grow rapidly and result in big changes. Weather predictability has been studied extensively in the past decades, and the weather prediction skills have been improving consistently. Now with the accurate weather prediction, we are ready to study weather controllability, the other side of a coin. Control is achieved by effective accumulation and combination of modifications or interventions like an orbit control of spacecraft. This session welcomes presentations about understanding of weather sensitivity and predictability, theoretical developments of controllability beyond predictability, weather modification techniques, and other related topics toward weather controllability.