A line-shaped rain band hit the Satsuma region of Kagoshima Prefecture on June 24, 2024, causing road flooding and suspending high-speed rail service [1, 2].

The extreme weather event disrupted critical transport infrastructure and triggered emergency warnings, highlighting the vulnerability of the region to sudden, intense precipitation caused by stagnant weather fronts.

The Japan Meteorological Agency (JMA) said the rain band formed between 8:48 and 8:50 JST [2]. The system produced torrential rainfall, with Satsumasendai City recording 108 mm of rain in a single hour [2]. Ichiki-Kurashino City saw 103 mm of rain during the same one-hour window [2].

Local authorities said the deluge led to road flooding in Satsumasendai City [2]. In response to the severity of the storm, the local weather office issued a Level 4 heavy-rain danger warning for Satsumasendai City [3].

The weather disrupted the Kyushu Shinkansen, the region's primary high-speed rail link. Service was suspended between Kagoshima-Chuo and Kumamoto stations [1, 2].

Meteorologists said the weather was caused by a stagnant Meiyu front. This front generated developed rain clouds that formed the line-shaped rain band, a phenomenon that significantly increases the risk of landslides and flash floods [1, 2].

JMA officials said the agency announced the occurrence of the rain band in the Satsuma region around 8:50 [1].

“Satsumasendai City recording 108 mm of rain in a single hour”

The occurrence of a line-shaped rain band during the Meiyu front season demonstrates the ongoing challenge Japan faces with 'guerrilla rainstorms.' The immediate suspension of the Kyushu Shinkansen and the issuance of Level 4 warnings illustrate a high-alert protocol designed to prevent casualties, as these specific weather patterns are known to trigger rapid-onset landslides in mountainous prefectures like Kagoshima.