The study evaluates ability of regional climate models (RCMs) to reproduce relationships between large-scale heavy precipitation events (LHPEs) over the Czech Republic and atmospheric circulation. We use an ensemble of 32 RCM simulations with the 0.11° resolution from the Euro-CORDEX project, and compare the historical simulations (1951–2005) against observations from the E-OBS data set. A novel selection criterion for LHPEs is proposed, defining these as days with at least 70% of all grid boxes over a given area with precipitation amounts exceeding the 90th grid-specific percentile of the seasonal distribution of daily amounts. The association with atmospheric circulation is investigated through circulation types derived from sea level pressure using airflow indices (direction, strength and vorticity). The majority of the RCMs capture that the frequency of days with LHPEs is higher in winter than summer, but almost all underestimate the occurrence of LHPEs in both seasons. In winter, the observed LHPEs are connected mainly with cyclonic types and westerly supertype; the role of nonwesterly and cyclonic-nonwesterly supertypes is significant only in the eastern part, where the Atlantic influence is weaker. In summer, the importance of cyclonic and nonwesterly types in producing LHPEs increases compared to winter. The RCMs reasonably well reproduce these links, including differences between seasons and regions, if their ensemble mean is evaluated, but large variations occur among individual simulations mainly in summer. The importance of cyclonic vorticity is overestimated in the RCMs, while westerly advection of moist air plays a smaller role in models than in observations.

该研究评估了区域气候模型（RCM）再现捷克共和国大规模强降水事件（LHPE）与大气环流之间关系的能力。我们使用来自 Euro-CORDEX 项目的 32 个 RCM 模拟集合，分辨率为 0.11°，并将历史模拟（1951-2005）与 E-OBS 数据集的观测结果进行比较。提出了一种新颖的 LHPE 选择标准，将这些天数定义为给定区域内至少 70% 的网格框的降水量超过日降雨量季节性分布的第 90 个网格特定百分位的天数。与大气环流的关联是通过使用气流指数（方向、强度和涡度）从海平面压力导出的环流类型来研究的。大多数 RCM 发现冬季 LHPE 发生的频率高于夏季，但几乎所有 RCM 都低估了两个季节 LHPE 的发生率。冬季观测到的LHPE主要与气旋型和西风超型有关；非西风和气旋-非西风超类型的作用仅在东部地区显着，而东部地区大西洋的影响较弱。与冬季相比，夏季气旋和非西风类型在产生 LHPE 方面的重要性有所增加。如果评估它们的整体平均值，RCM 可以很好地再现这些联系，包括季节和地区之间的差异，但各个模拟之间主要在夏季会出现很大的变化。RCM 中气旋涡度的重要性被高估，而湿空气的西风平流在模型中的作用比在观测中的作用要小。