Interactions between organised deep convection and large-scale scale circulations are increasingly recognised to play a crucial role in shaping atmospheric dynamics. Convective organisation itself depends on smaller-scale interactions involving individual convective plumes and cloud microphysical processes. A cascade of interactions across scales thereby underpins mesoscale convective systems and other meteorological phenomena that drive extreme hydroclimatic events. Understanding these interactions is important for assessing changes in hazardous convective weather and its impacts in a warming climate. Challenging the conventional assumption of strict scale separation, these interactions may also be key to understanding persistent discrepancies between observed and simulated regional climate change.

Global kilometre-scale atmospheric models and multidecadal observations over large domains are opening new opportunities to gain insights into the role of mesoscale convection in shaping circulation patterns for the first time. This session aims to brings together recent advances in understanding how atmospheric convective scale-interactions feedback on larger-scale circulations, and influence local and downstream climate extremes and their changes under warming. The session is intended to translate advances in modelling and observations into improved physical understanding of atmospheric dynamics.

We invite contributions focusing on mesoscale convective system dynamics and cloud microphysics, upscale effects of convection, and large-scale controls on convective organisation. Relevant contributions include advances in high-resolution modelling, forecasts and climate projections of these interactions, and insights from novel observations. We also invite contributions on the processes driving the formation and evolution of organised deep convection, and how these factors shape spatio-temporal patterns of deep convective intensity, precipitation, and on-the-ground hazards. This includes, but is not limited to, contributions on land-convection interactions in connection with mesoscale and severe storms. Examples include effects of complex topography, soil moisture feedbacks, and land use or land-use change, such as urbanisation, deforestation, or irrigation. We welcome diverse perspectives towards advancing physical understanding of convective processes, and quantifying their interactions across scales.