Performance of Kilometer-Scale CARAS Precipitation Product Against Ground-based Observations During 2008–2021 over Hubei, China

<p indent="0mm">Based on rain gauge data during 2008–2021 from national meteorological observation stations, this study investigated the performance of the precipitation field from the 1-km-resolution version of the China Atmospheric Realtime Analysis (CARAS) over Hubei from the perspective of climatology, multiple-time scale variations, as well as fusion accuracy and detection capability at multiple temporal scales. The results show that CARAS precipitation can reproduce the spatial distribution patterns of climatological seasonal precipitation and rainy days well over the whole of Hubei compared with observational (OBS) precipitation, albeit deviations exist between CARAS and OBS in terms of magnitude. Moreover, high correlation and consistency between CARAS and OBS can be found in multiple-time scale variations over Hubei, with correlation coefficients of interannual, seasonal, and diurnal variation generally exceeding 0.85, 0.98, and 0.95, respectively. Furthermore, CARAS has a relatively higher fusion accuracy in summer and winter, and stronger/weaker detection capability in spring/winter at a daily scale. However, the detection capability of CARAS at an hourly scale is weaker than that at a daily scale. With different precipitation intensity levels considered, CARAS daily precipitation shows relatively higher fusion accuracy in estimating moderate and heavy rain, and better detection capability in capturing no rain events. The variations of accuracy metrics and detection metrics under different precipitation intensities at an hourly scale generally resemble those at a daily scale. However, CARAS precipitation at an hourly scale shows a relatively lower fusion accuracy and weaker detection capability compared with that at a daily scale. This paper provides an insight into the characteristics of systematic deviations in CARAS precipitation over Hubei, which will benefit relevant applications of CARAS in meteorological operations over Hubei and the improvement of CARAS in the future.