Significance: The deep clouds that make up tropical disturbances, the precursors to more intense tropical cyclones (TCs) (including hurricanes and typhoons), effectively trap infrared radiation emitted by Earth’s surface and lower atmosphere. Our results demonstrate that the local atmospheric warming caused by this “cloud greenhouse effect” is a key trigger for promoting and accelerating the evolution of such precursor storms into intense TCs. The forecasting of TC formation remains extremely challenging, while the representation of cloud processes and their feedback with radiation is a large source of uncertainty in the numerical models that forecasts rely upon. Our results suggest that focusing future research on constraining these processes in models holds promise for key progress in the prediction of these devastating storms.

Overshooting top (OT), a proxy for deep convection with an intense updraft that can penetrate the tropopause, has an important influence on typhoon intensification. Using 9003 Himawari‐8 satellite images and a unique OT detection algorithm, the diurnal variation of OTs within 45 western North Pacific typhoons were analyzed. We examined the distribution of OTs in different types of typhoons in terms of both intensity and intensity change and the relationship between the OTs and typhoon intensification on a diurnal scale. Our results show that a greater OT density (OTD) occurs in strong typhoons and rapid intensification (RI) typhoons. Moreover, RI typhoons showed greater diurnal variation than non‐RI typhoons. The diurnal cycle of OTD in RI typhoons was in phase with the intensification of the typhoon, with the maximum in the early morning. Therefore, OTD can become a potentially effective indicator to estimate diurnal changes in typhoon intensity.

This work examines the impacts of the diurnal radiation contrast on the contraction rate of the radius of maximum wind (RMW) during intensification of Hurricane Edouard (2014) through convection-permitting simulations. Rapid contraction of RMW occurs both in the low and midlevels for the control run and the sensitivity run without solar insolation, while the tropical cyclone contracts more slowly in the low levels and later in the midlevels and thereafter fails to intensify continuously in the absence of the night phase, under weak vertical wind shear (~4 m s−1). The clouds at the top of the boundary layer absorb solar shortwave heating during the daytime, which enhanced the temperature inversion there and increased the convective inhibition, while nighttime destabilization and moistening in low levels through radiative cooling decrease convective inhibition and favor more convection inside the RMW than in the daytime phase. The budget analysis of the tangential wind tendency reveals that the greater positive radial vorticity flux inside of the RMW is the key RMW contraction mechanism in the boundary layer at night because of the enhanced convection. However, the greater positive vertical advection of tangential wind inside of the RMW dominates the RMW contraction in the midlevels.

Recent composite analysis of landfalling tropical cyclones (TCs) suggests a rain rate peak in the early morning, which contradicts the typically observed peak in convective precipitation over land seen in the late afternoon to early evening. We conducted a set of idealized simulations of TCs and analyzed observational data from TC Bebinca (2018), which stalled near the shoreline of southern China. We show a distinct land–sea contrast in the diurnal variation of TC precipitation and an 8–12 hr offset between the peak precipitation time over land compared with that over the sea in a TC that stalls at the shoreline. The highest land surface temperature and maximum low‐level buoyancy during the afternoon led to peak precipitation over land at this time. However, the peak precipitation over the sea in the early morning was generated by the increase in relative humidity caused by nighttime radiative cooling and enhanced instability.

Tropical cyclone (TC) translation speed often affects the time of strong wind attacks and precipitation accumulation in the areas that TCs pass through. Therefore, the trend of TC translation speed has important implications for TC-related risks in the current and future climate. In this paper, the trends of TC translation speed over the Western North Pacific (WNP) from 1980 to 2018 are analyzed, and TC lifetime maximum intensity (LMI) is proposed as a factor related to the interdecadal change of translation speed. During the periods with accurate data, 1980–1997 shows a decreasing trend in TC translation speed while an increasing trend was found in 1998–2018. The main lifetime period contributing to a TC translation speed change is before the occurrence of the LMI. The change in the trend is related to both the TC’s characteristics itself and the environmental factors. For the period 1998–2018, an increasing trend of TC intensity has a significant influence on the trend of translation speed. For the environmental factors, a trend of east wind enhancement at and above 500 hPa as the steering flow is found mostly correlated in the active TC region of the WNP with westward translation before reaching LMI, accompanied by a weakening trend of 200–850 hPa vertical wind shear, and an increasing trend of potential intensity.

The sensitivity of the secondary eyewall formation (SEF) of Hurricane Edouard (2014) to the diurnal solar insolation cycle is examined with convection-permitting simulations. A control run with a real diurnal radiation cycle and a sensitivity experiment without solar insolation are conducted. In the control run, there is an area of relatively weak convection between the outer rainbands and the primary eyewall, that is, a moat region. This area is highly sensitive to solar shortwave radiative heating, mostly in the mid- to upper levels in the daytime, which leads to a net stabilization effect and suppresses convective development. Moreover, the heated surface air weakens the wind-induced surface heat exchange (WISHE) feedback between the surface fluxes (that promote convection) and convective heating (that feeds into the secondary circulation and then the tangential wind). Consequently, a typical SEF with a clear moat follows. In the sensitivity experiment, in contrast, net radiative cooling leads to persistent active inner rainbands between the primary eyewall and outer rainbands, and these, along with the absence of the rapid filamentation zone, are detrimental to moat formation and thus to SEF. Sawyer–Eliassen diagnoses further suggest that the radiation-induced difference in diabatic heating is more important than the vortex wind structure for moat formation and SEF. These results suggest that the SEF is highly sensitive to solar insolation.