Synergistic Influences from High, Middle, and Low Latitudes on the Extreme Precipitation Events in the Beijing-Tianjin-Hebei Region During the Summer of 2023

East Asia is a region characterized by a typical monsoon climate, which is accompanied by strong precipitation with complex spatiotemporal variability during summer. Previous works have emphasized the impact of tropical signals on extreme summer precipitation over East Asia, but the roles of the mid-high latitude cyclones are still unclear. Using a reanalysis dataset, this study discloses the synergistic influences of anomalous signals from different latitudes on the extreme precipitation event in the Beijing-Tianjin-Hebei (BTH) region during the summer of 2023. The main conclusions are obtained as follows: the decreased sea ice density caused more Arctic cyclones to generate at positions further west in the Barents Sea and the west of the Kara Sea and then move southeast to East Asia in 2023. Furthermore, the synergistic influences of the outward Arctic cyclones and anomalous signals from middle and low latitudes are discussed. First, the significant northward jump of the Western Pacific Subtropical High (WPSH) provided the favorable condition of large-scale background circulation for summer precipitation in the BTH region in 2023. In addition, the southward intrusion of the Arctic cyclones and the mid-latitude zonal wave trains transported massive cold air to the BTH region. Subsequently, the cold air masses met with the warm moist air carried by the landfall typhoon ‘Doksuri’, which generated strong fronts and triggered the extreme precipitation on July 29. However, another severe typhoon, ‘Kanu’, generated and moved northward from the tropical Pacific, which caused the further northward shift of the WPSH and the termination of this persistent extreme precipitation on August 1.