We introduce the idea of simultaneous heavy precipitation events (SHPEs) to understand whether extreme precipitation has a spatial organization manifested as specified tracks or contiguous fields with inherent scaling relationships. For this purpose, we created a database of SHPEs using ground‐based precipitation observations recorded by the daily Global Historical Climatology Network across the conterminous United States during 1900–2014. SHPEs are examined for their seasonality, spatial manifestation, orientation, and areal extent. We quantified the spatial distribution of the centroids and principal axes of SHPEs and their quasi‐elliptical manifestations, azimuthal orientations, and areal extents on the ground. Four seasons, December‐January‐February (DJF), March‐April‐May (MAM), June‐July‐August (JJA), and September‐October‐November (SON) are considered to examine the spatial patterns and associated large‐scale atmospheric circulations. Results indicate that there are 54, 58, 103, and 204 SHPEs in DJF, MAM, JJA, and SON seasons, and their longest stretches range on average between 650 and 1,600, between 850 and 1,500, between 950 and 1,550, and between 750 and 1,450 km, respectively. SHPEs in the DJF, MAM, and JJA seasons occur mostly over the Pacific coast and central and midwestern United States, respectively. The atmospheric circulation patterns and mechanisms of precipitable water vapor and moisture transport in the atmosphere are also discussed in relation to these SHPEs. Power laws explain SHPEs' underlying area scaling behavior in all the four seasons, with stronger evidence in DJF and MAM. A seasonal spatial risk model is developed to predict the likelihood of SHPEs. Quantifying the characteristics of SHPEs and modeling their footprints can improve the projections of flood risk and understanding of damages to interconnected infrastructure systems.

中文翻译：

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了解美国本土同时发生的强降水事件（SHPE）的空间组织

我们引入同时发生强降水事件（SHPEs）的概念，以了解极端降水是否具有表现为特定轨道或具有固有比例关系的连续场的空间组织。为此，我们使用1900-2014年间全美各地的每日全球历史气候学网络记录的地面降水观测资料建立了SHPEs数据库。检查SHPE的季节性，空间表现，方向和面积。我们量化了SHPEs质心和主轴的空间分布，它们的{准椭圆}表现，方位角取向和地面范围。四个季节，即12月-1月-2月（DJF），3月-4月-5月（MAM），6月-7月-8月（JJA），以及9-10月（SON）用于检查空间格局和相关的大规模大气环流。结果表明，在DJF，MAM，JJA和SON季节中，有54、58、103和204个SHPE，它们的最长延伸时间平均在650–1600、850–1500、950–1550和750–1450之间km。DJF，MAM和JJA季节的SHPE分别分别发生在美国的太平洋海岸，中部和中西部。还与这些SHPE讨论了{大气循环模式}以及大气中可沉淀的水蒸气和湿气传输的机理。幂律解释了SHPEs在所有四个季节中的潜在区域尺度变化行为，DJF和MAM中有更充分的证据。建立了季节性空间风险模型以预测发生SHPE的可能性。量化SHPE的特征并对其足迹进行建模可以改善洪水风险的预测和对互连基础设施系统的破坏的了解。