Accurate tropical cyclone (TC) risk assessment is challenged by limited historical TC records. In this paper, a statistical–dynamical model is developed to generate a large TC hazard dataset over the western North Pacific (WNP) basin for risk assessment. The model integrates three core components: a fully statistical TC genesis model, an environment-dependent beta-advection TC track model (BAM) for trajectory simulation, and a set of nonlinear differential equations governing TC intensification rates. Using this model, a 10,000-yr synthetic TC dataset is generated and systematically validated against observational records. The results show that the model reproduces observed TC climatology, including seasonal cycle, genesis statistics, track density, and intensity distribution. Regional TC hazard analysis via landfall intensity return period curves across the WNP shows reasonable model performance. It is thus believed that the proposed statistical–dynamical model has the potential to be used for supporting TC risk assessments in coastal regions, including those with limited observational data.

Activities of tropical cyclones (TCs) over the Bay of Bengal (BoB) often exert appreciable influences on precipitation in China, but how and to what extent these influences operate remain unclear. This study utilizes the International Best Track Archive for Climate Stewardship (IBTrACS) dataset and infrared satellite images from Japan during 1996–2021 to analyze the cloud system structure patterns associated with BoB TCs (excluding tropical depressions) and their impact on China rainfall. A fuzzy c–means clustering method was employed to classify TC cloud clusters into three morphological types: Type “6” (T6) and Type “9” (T9), with cloud distributions predominantly located north (south) of the TC center; and type “symmetry” (TSM), with relatively balanced cloud distributions on both sides. The results indicate that T6 (41.3%) occurs most frequently in autumn, T9 (31.2%) peaks in early summer, and TSM (27.5%) also shows a slight preference for autumn. Distinct circulation features are associated with each type. At 500 hPa over the Qinghai–Xizang Plateau (QXP), T6 is associated with the southern branch trough, T9 with straight westerlies, and TSM with a ridge. At 200 hPa, both centers of T6 and TSM are located at the periphery of the South Asian high (SAH), with enhanced upper-level divergence outflows, resulting in northward extension of cloud clusters under the influence of the westerly jet. In contrast, T9 TCs are embedded within the SAH, where weaker divergence outflows restrict northward cloud development. All three types are characterized by a column-integrated water vapor channel extending from the BoB to southern China, with T9 exhibiting the strongest moisture transport to China. Precipitation analyses reveal that all three types contribute to rainfall in Yunnan Province and the Guangxi Zhuangzu Zizhiqu. Moreover, T6 produces heavier rainfall in southern Xizang Zizhiqu (abbreviated as Xizang hereafter), T9 in Yunnan Province, and TSM in Sichuan Province and Xizang. Remote precipitation induced by TC long-distance moisture transport also exhibits distinct patterns: under T6, high-rainfall areas are widely distributed across southwestern China and parts of southern China; under T9, heavy rainfall is concentrated in southern China; and under TSM, heavy rainfall is mainly confined to Guangdong and Jiangxi provinces. These results provide useful insights for precipitation forecasting in China based on the cloud cluster patterns of the BoB TCs.

Tropical cyclones (TCs), including tropical depressions and different categories of typhoons, hurricanes, and cyclonic storms, mostly originate over the oceans in the absence of direct observations. Thus, detailed monitoring and analysis of TCs has always been an unsolved problem. In the recent 20 years, great changes have taken place in domestic and foreign TC monitoring techniques, imposing a significant impact on TC operations and research. Some new technologies and products gradually emerge to support operations, with improved monitoring accuracy. In this paper, the progress on TC monitoring and analysis via meteorological satellites, radars, and airplanes in China and the world is reviewed, compared, and summarized, with special focuses on multisatellite fusion observations, in situ aircraft measurements, and some unconventional observation equipment such as rockets, saildrones, and underwater gliders. On this basis, the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.

The Bay of Bengal (BoB) tropical cyclones (TCs) and the Tibetan Plateau vortices (TPVs) are two crucial weather systems influencing the Tibetan Plateau (TP). Their synergistic effects can lead to widespread heavy precipitation events on the TP. In this study, we employ the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to track the trajectory of water vapor transport during three large-scale precipitation events on the TP under the combined influence of BoB TCs and TPVs. The results indicate that low-level water vapor from the BoB under the influence of BoB TCs was cyclonically entangled into the cyclonic circulation, lifted and transported northward by southwesterly flow to the southeastern part of the TP, which contributes to the moistening of the entire troposphere there. Additionally, convergence of the cyclonic circulation of the TPVs on the northern TP further transports water vapor collected in the southeastern TP northward, conducive to the maintenance and development of precipitation systems, thus inducing widespread heavy precipitation events over the TP.

Tropical cyclones over the Bay of Bengal (BoBTC) affect the precipitation over China, with distinct seasonal and daily variabilities. This study quantitatively examines the daily standardized precipitation anomalies (SPAs) over China on the days with BoBTC activities (storm-days) and related circulations, based on rainfall measurements at surface meteorological stations and ECMWF reanalysis data on a 0.25° × 0.25° resolution during 1979–2019. Significant positive SPA is found over the stations in the two adjacent regions around BoB (Southwest China in May/November and southern Tibetan Plateau in October) and three distant regions (Southeast China and the northeastern boundary of the Qinghai–Tibet Plateau in May, and central North China in October). The SPA distributions are remarkably consistent with the integrated water vapor transport (IVT) anomalies. Enhanced IVT is found associated with the interaction between southwesterly (southerly) of the BoBTC circulation and low-level monsoonal flow in May (midlevel westerly in winter months). The probabilities of extreme precipitation (EP) occurrences over the above regions all increase on storm-days. For adjacent regions, EP is significantly correlated with the northward IVT anomalies to the east of BoBTC circulation, which strengthen the water vapor input through the southern border. Such IVT anomalies are stronger in May, benefited by the deep monsoonal southwesterlies than those in November. For distant regions, EP is more closely related to the IVT anomaly extending back from BoB. Enhanced moisture from BoB concentrates along a local low-level convergence line over Southeast China, being further facilitated by coexistence of the BoBTC depression and midlevel westerly trough in midlatitudes. Our results highlight the interactions between BoBTCs and local weather systems that influence the general precipitation anomalies and occurrence of EP over China, especially over distant regions.