Convection‐Permitting Hindcasting of Diurnal Variation of Mei‐yu Rainfall Over East China With a Global Variable‐Resolution Model

Abstract

Mei-yu is a unique climatic feature associated with frontal systems during the northward propagation of the East Asian summer monsoon that produces abundant rainfall particularly in the Yangtze-Huaihe River basin (YHRB), West Japan (called Baiu), and South Korea (called Changma) (e.g., Ding, 1992;Tao & Chen, 1987). During the Mei-yu season, the western Pacific subtropical high (WPSH) is zonally aligned with the ridge extending from southern Japan to southern China. The warm and moist air transported by the East Asian summer monsoon interacts with the cold air from mid-to-high latitudes, forming a stationary front with a southwest-northeast orientation stretching from the YHRB of China to southern Japan (Ding et al., 2020). The Mei-yu season over the YHRB that typically occurs between mid-June to mid-July is a period with frequent heavy precipitation along the Mei-yu front (e.g., Bao et al., 2011;Ding, 1992). Anomalies of the Mei-yu rainfall, including its duration, amount, and diurnal variation, often result in droughts or floods in the YHRB and cause numerous casualties and enormous property losses (e.g., Dai et al., 2008;Fu et al., 2020). Therefore, a better understanding of Mei-yu rainfall has valuable implications for precipitation prediction and emergency preparedness (e.g., Li et al., 2019;Sampe & Xie, 2010).The diurnal variation of precipitation plays an important role in local and global weather and climate, and can considerably affect the energy and hydrological cycles (e.g., Dai, Giorgi, & Trenberth, 1999;Dai, Trenberth, & Karl, 1999). Due to the effect of surface heterogeneity such as complex land-sea contrast and irregular mountain-valley distributions, the diurnal variation of summer-time rainfall over China exhibits

Subseasonal Predictability of the July 2021 Extreme Rainfall Event Over Henan China in S2S Operational Models

“…Upgrades to higher horizontal model resolution will allow a better representation of typhoon effects. Using high‐resolution convective permitting models for S2S TC prediction appears very promising (M. Xu et al., 2021; Risanto et al., 2022).…”

Numerical Weather Prediction at 200 m Local Resolution Based on an Unstructured Grid Global Model

“…Its dynamical core solves a set of fully compressible non‐hydrostatic equations using the finite‐volume method, discretized horizontally on a C‐grid staggered unstructured spherical centroidal Voronoi tessellation (SCVT) (Ringler et al., 2010; Thuburn et al., 2009) and vertically in a geometric‐height hybrid terrain‐following coordinate (Klemp, 2011). MPAS‐A has been used for applications such as medium‐range convection‐permitting ensemble forecasts (Schwartz, 2019), study of spatial and temporal wind speed variability during open cellular convection (Imberger et al., 2021), diurnal variation of Mei‐yu rainfall over East China (Xu et al., 2021), investigation of western North Pacific tropical cyclone tracks and intensities (Lui et al., 2021), etc. Modifying the source code of MPAS‐A, we extend the model to cover usages where one would conventionally use WRF with domain nesting for high‐resolution simulations around a region of interest.…”

Appropriately representing convective heating is critical for predicting catastrophic heavy rainfall in 2021 in Henan Province of China

“…Jeworrek et al (2021) revealed that the GF scheme performed better for summertime convective precipitation, but the KF parameterization better simulated wintertime frontal precipitation over the complex terrain of southwest British Columbia. Furthermore, previous studies have also pointed out that simulations with convective parameterizations exhibited large deficiencies in capturing precipitation intensity and frequency and failed to reproduce the diurnal variation of heavy precipitation (e.g., Dai 2006, Stephens et al 2010, Lin et al 2017, Xu et al 2021. For instance, Li et al (2020) found that the simulation with convective parameterization underestimated the entire warm-season precipitation intensity during the East Asian summer monsoon.…”

“…Previous studies have suggested that increasing grid horizontal resolution could significantly improve the capability to simulate extreme precipitation because the impacts of topography, land use, and other important processes are better resolved (Bacmeister et al 2014, Prein et al 2015. For weather prediction, many studies have shown that when the model resolution increases to convection-permitting scale, the spatial and temporal distributions, diurnal variations, and intensity of precipitation can be predicted more accurately (Zhu et al 2018, Zhao et al 2019, Xu et al 2021. Zhu et al (2018) indicated that the convection-permitting forecasts of precipitation in China during the summer of 2013-2014 outperform global forecasts in terms of spatial distribution, intensity, and diurnal variation.…”