Northward shift of the Tibetan Plateau vortex street-like system intensifies mid- and late-summer rainfall extremes in Beijing

During 24–28 July 2025, Beijing and its surrounding regions experienced a record-breaking rainfall event that triggered severe flooding, resulting in substantial economic losses and casualties. Here we show that this extreme rainfall was strongly influenced by a vortex street–like system in the wake of the Tibetan Plateau (TPVSL), a large-scale dynamical feature that constitutes a key mechanism within the East Asian subtropical main rain belt. Using daily reanalysis data and precipitation observations, we demonstrate that the TPVSL provided the background circulation field for more than 90% of the rainfall during this event. The propagation line of the TPVSL exhibited an anomalous northward displacement in July 2025, closely linked to the abnormal northward position of the Western Pacific Subtropical High (WPSH). In contrast, the vortex propagation speed and shedding period of the TPVSL remained comparable to climatological conditions. We further show that the July 2025 northward shift of the WPSH is consistent with a long-term trend, as the WPSH has migrated northward by 1–2° latitude during July–August from 1979 to 2024. This secular displacement has driven a concurrent northward shift of the TPVSL propagation line, resulting in increasing summer rainfall and heavy precipitation events in northern China, including the Beijing region. Our findings highlight the crucial role of the TPVSL system in shaping extreme rainfall in North China and provide a new perspective for understanding and mitigating flood risk in Beijing.