The UK Met Office's Daily Weather Reports (DWR) contain extensive logs of UK thunderstorm activity. To date, only a very small fraction of these data have been digitized as part of the MIDAS dataset, and exclusively after 1950. Using the recently‐scanned UK Met Office Monthly Weather Reports (MWR), which are based on a subset of the observations that form the DWR, we here provide digitized data and a summary of thunderdays from 10 long‐running British stations over the period 1884–1993. The data are presented ‘as is’, with no attempt to provide any corrections or calibration. For 4 of the 10 stations, thunderday observations were discontinued at various times between 1949 and 1964, and it is necessary to switch to a neighbouring station in order to continue the series. Approximately half the series exhibit sharp drops in thunderdays at various points between 1960 and 1990, although none are coincident with known station changes. Comparison with nearby MIDAS stations suggests the low thunderdays are the result of changes in observing practice, rather than genuine changes in thunderstorm occurrence. These potential data issues limit interpretation of the long‐term trends. However, it can nevertheless be concluded that none of the stations show the expected increase in thunderdays as a result of the rise in surface temperature over the 20th century. In order to provide more quantitative determination of the long‐term trends in thunderstorm occurrence, we advocate further digitization efforts to recover the data from the numerous stations in the MWRs, and subsequent analysis of the common signals across neighbouring stations.

中文翻译：

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1884年至1993年，英国十个地点发生雷暴

英国气象局的每日天气报告（DWR）包含有关英国雷暴活动的大量日志。迄今为止，只有极少数数据作为MIDAS数据集的一部分被数字化，并且仅在1950年之后被数字化。使用最近扫描的英国气象局月度天气报告（MWR），该报告基于观测的子集作为DWR的数据，我们在此提供数字化数据和1884–1993年间来自10个长期运行的英国气象站的雷电摘要。数据按“原样”显示，未尝试提供任何校正或校准。对于10个台中的4个，在1949年至1964年之间的不同时间中断了雷声观测，因此有必要切换到相邻台以继续进行该系列。尽管没有一个与已知的台站变化相吻合，但大约有一半的系列在1960年至1990年之间的不同时间点雷暴下降。与附近的MIDAS站进行比较表明，雷雨天偏低是观测实践变化的结果，而不是雷暴发生的真正变化。这些潜在的数据问题限制了对长期趋势的解释。但是，可以得出结论，由于20世纪地表温度的升高，没有一个台站显示出预期的雷雨天增加。为了更定量地确定雷暴发生的长期趋势，我们提倡进一步的数字化工作，以从MWR的众多站点中恢复数据，