An Observational Analysis of a Persistent Extreme Precipitation Event in the Post-Flood Season over a Tropical Island in China

Featuring unique tropical land–sea contrast and mesoscale terrain, Hainan Island in China is endowed with active convections of special regional characteristics. Persistent extreme precipitation events (PEPs) during the post-flood season, triggered by multi-scale interactions among mid-latitude weather systems, exhibit notable features, long duration high rainfall rates low forecasting performance. This study motivated a failure to forecast PEP two stages distinct characteristics predictabilities, season over on 16–18 October 2020. Based multiple sources remote sensing high-resolution rain gauge records, detailed observational analyses were conducted using flow decomposition method. Water vapor divergence (WVD) its three components used investigate spatial distribution temporal evolution predictabilities this PEP. Decomposed moisture can be determine how what extent large- sub-synoptic scale convergence contributes PEPs tropics, under similar synoptic backgrounds. Joint applications data decomposed WVD are proposed further assist predicting terms location evolution.