Adv Atmos Sci 2021 Apr 6:1-14. Epub 2021 Apr 6.
Climate Prediction Center, NCEP/NOAA, College Park, MD 20740 USA.
The record-breaking meiyu in the Yangtze-Huaihe River valley (YHRV) in 2020 was characterized by an early onset, a delayed retreat, a long duration, a wide meridional rainbelt, abundant precipitation, and frequent heavy rainstorm processes. It is noted that the East Asian monsoon circulation system presented a significant quasi-biweekly oscillation (QBWO) during the meiyu season of 2020 that was associated with the onset and retreat of meiyu, a northward shift and stagnation of the rainbelt, and the occurrence and persistence of heavy rainstorm processes. Correspondingly, during the meiyu season, the monsoon circulation subsystems, including the western Pacific subtropical high (WPSH), the upper-level East Asian westerly jet, and the low-level southwesterly jet, experienced periodic oscillations linked with the QBWO. Read More