Plain Language Summary
Interplays between radiation, clouds and convection are well studied in numerical simulations under idealized boundary conditions (e.g., spatially uniform sea surface temperatures, no wind shear, etc.). However, it remains unclear how they interact with each other in more realistic situations with the presence of sea surface temperature gradients and a large-scale background circulation. In this study we examine the impact of synoptic-scale radiative coupling on convective organization, clouds, and precipitation extremes using a ~50 km resolution atmospheric general circulation model. When synoptic-scale radiative coupling is disabled, we find that the mean circulation and rainfall remain almost unaffected. However, convection becomes less organized without radiative coupling, which is due to the diminished spatial contrast in radiative cooling between dry and moist regions. Also, both daily precipitation and mid-tropospheric updrafts exhibit a reduction in the probability of their extreme values when radiative coupling is disabled. In addition, we find that radiative coupling can modulate the distribution of clouds and relative humidity. These findings highlight the importance of synoptic-scale interactions between radiation and convection even in realistic situations, and motivates the comparison of model simulations and observations.