Abstract:Typhoon rainstorm disaster tops the three types of disasters (rainstorm, gale, storm surge) of typhoon and extreme precipitation of typhoon is the direct cause of rainstorm disaster. The study on extreme precipitation of typhoon is helpful to enhance the understanding of its mechanism and to improve the forecast of extreme precipitation. The strong Typhoon FITOW (2013) has the characteristics of strong intensity as landing, intense precipitation, wide range of influence, and severe disaster caused by it. In this paper, the characteristics and formation mechanism of the extreme precipitation of Typhoon FITOW are reviewed and summarized. The heavy precipitation process of FITOW is mainly divided into two stages, resulting in two heavy precipitation centers in the area of Hangzhou Bay and the junction of Zhejiang and Fujian provinces. The extreme precipitation of FITOW is due to the multi-scale interaction of environmental factors, terrain, and internal conditions. Environmental factors involve the effect of double typhoons, the intrusion of weak cold air, typhoon inverted trough, vertical wind shear, and upper-level jet stream, among which the continuous water vapor transport by the easterly jet outside of Typhoon DANAS is the key physical factor for the extreme precipitation of FITOW; the topographic enhancement effect is an important reason for the rarely seen heavy precipitation in Yuyao, Zhejiang; the convergence and condensation of water vapor, the melting of graupel, and the migration of raindrops in convective areas are the important internal factors for the rainstorm amplification.