Typhoon Hagibis (2019) caused widespread flooding and damage over eastern Japan. The associated rainfall maxima were primarily observed on the windward mountain slopes along with the west of the leading edge of a low-level front. Concomitantly, a significant positive value in sea surface temperature anomalies (SSTAs) was observed in association with an ocean eddy over the Oyashio region, together with anomalous warmth over the entire western North Pacific. The present study examines the role of the SSTAs in the rainfall distribution associated with Hagibis, to deepen our understanding of the influence of the midlatitude ocean on tropical cyclones and associated rainfall. Our sensitivity experiments demonstrate that the observed warm SSTAs had the potential to displace the rainfall caused by Hagibis inland and thereby acted to increase precipitation along the Pacific coast of northeastern Japan. Our results suggest that midlatitude SSTAs on ocean-eddy scales can also influence the synoptic-scale atmospheric front and associated heavy rainfall.

台风哈吉比斯（2019）在日本东部造成了大面积的洪水和破坏。相关的降雨最大值主要是在顺风山坡以及低空锋前沿的西边观察到的。同时，与Oyashio地区上的海洋涡流以及整个北太平洋西部地区的异常温暖相伴，海表温度异常（SSTAs）出现了显着的正值。本研究探讨了SSTAs在与Hagibis相关的降雨分布中的作用，以加深我们对中纬度海洋对热带气旋和相关降雨的影响的理解。我们的敏感性实验表明，观测到的温暖的SSTAs可能替代了由Hagibis内陆引起的降雨，从而起到了增加日本东北太平洋沿岸降水的作用。我们的结果表明，海洋涡尺度的中纬度SSTA也会影响天气尺度的大气锋和相关的强降雨。