The clouds in a tropical cyclone (TC) exhibit a large variety of processes and forms due to the underlying vortex dynamics. For physically realistic numerical simulations of TCs, the cloud processes must be adequately resolved or parameterized. Current operational numerical weather prediction (NWP) models for TC simulation and forecasting have a horizontal grid size on the order of 1 km, which is convection-permitting but not sufficient to resolve individual convective cells fully (e.g., Bryan et al., 2003;Moeng et al., 2010). Including subgrid parameterization of convection in the physics configuration is a practical means to account for the effect of unresolved convection on the resolved TC dynamics.For practical uses in NWP models, scale-adaptive algorithms of convective mass flux have been introduced into traditional quasi-equilibrium convection parameterization schemes that can be used at convection-permitting resolutions (

Adequate representation of the subgrid‐scale (SGS) turbulent fluxes associated with convective clouds in the eyewall and rainbands above the boundary layer is important for simulating the formation of tropical cyclone (TC) dynamic and thermal structure, as well as the evolution and intensification of the TC. Two sets of benchmark large‐eddy simulations (LESs) for an idealized TC during the rapid intensification and mature stages were conducted. The turbulent transport above the boundary layer in the TC eyewall and rainbands exhibits a remarkable countergradient characteristic, which is poorly represented by the traditional eddy‐diffusivity closure. In contrast, the H‐gradient closure based on the horizontal gradients of the resolved variables is capable of accurately capturing the countergradient features and exhibiting a spatial distribution of SGS fluxes that mimics much better the coarse‐grained fluxes from the LES benchmarks. Moreover, the H‐gradient closure allows for the backscatter transfer of energy. By implementing the H‐gradient closure into a three‐dimensional turbulence parameterization, the TC simulated using the modified parameterization bears closer resemblance to the LES benchmarks in terms of the spatial distribution of SGS fluxes, TC intensity, primary and secondary circulations, and cloud morphology.