Recent flooding related to extreme precipitation in the UK has highlighted the importance of better understanding these events. Many studies have quantified annual exceedance probabilities (or return periods) for UK extreme daily precipitation using fixed regions (e.g., HadUKP) and region of interest (ROI) (e.g., Flood Estimation Handbook) approaches, although fewer have evaluated short‐duration events, which are important for flash flooding. Existing UK extreme precipitation regions are based on daily datasets which have different characteristics compared to sub‐daily extremes, and their application to quantify short‐duration extremes may therefore be inappropriate. We use a recently available, quality‐controlled hourly precipitation dataset for the UK from 1992 to 2014 to derive various extreme precipitation indices (e.g., annual maxima, 0.99 quantile) which are combined with additional climatological variables (e.g., temperature), geographical characteristics (e.g., latitude), and weather patterns (WPs) to characterize the UK hourly extreme precipitation climatology and to define five new hourly extreme regions. These regions fulfil regional homogeneity and discordancy statistical measures, and reflect the dynamical processes associated with the weather pattern categorisation defined over the UK and surrounding European area. Thereafter, we use regional frequency analysis (RFA) to fit generalized extreme value (GEV) and generalized Pareto (GP) distributions to 1 hr annual maxima (AMAX) and 0.99 quantile (Q99) precipitation, respectively, to calculate regional annual probability estimates (AEP) for 20%, 10%, and 2% (i.e., 5‐, 10‐, and 50‐year return periods). The new regions capture the spatial variation of hourly precipitation across the UK. Furthermore, the AEP estimates using both distributions are similar for each region. Finally, the WPs associated with the frequency and intensity of the most extreme hourly precipitation accumulations are not identical to results reported by others for daily precipitation.

中文翻译：

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英国每小时的新极端降水区域和区域年度概率估计

最近与英国极端降水有关的洪水突出了更好地了解这些事件的重要性。许多研究使用固定区域（例如，HadUKP）和关注区域（ROI）（例如，洪水估算手册）方法量化了英国极端每日降水的年度超标概率（或回归期），尽管评估短期事件的评估较少，这对于山洪泛滥很重要。英国现有的极端降水区域是基于与次日极端相比具有不同特征的每日数据集，因此将其用于量化短期持续性极端情况可能是不合适的。我们使用1992年至2014年间英国最近可用的，质量控制的每小时降水数据集来得出各种极端降水指数（例如，年度最大值0。99分位数）与其他气候变量（例如温度），地理特征（例如纬度）和天气模式（WPs）相结合，以表征英国每小时极端降水气候特征并定义五个新的每小时极端气候区域。这些地区完成了地区同质性和不一致统计措施，并反映了与英国及欧洲周边地区定义的天气模式分类相关的动态过程。之后，我们使用区域频率分析（RFA）分别将广义极值（GEV）和广义Pareto（GP）分布拟合为1小时年度最大值（AMAX）和0.99分位数（Q99）降水量，以计算区域年度概率估计值（ AEP）获得20％，10％和2％（即5年，10年和50年的回报期）。新地区捕捉了英国每小时降水的空间变化。此外，对于每个区域，使用两种分布的AEP估算值都相似。最后，与最极端的每小时降水量累积的频率和强度相关的WP与其他人报告的每日降水量结果不同。