A double typhoon is approaching the Japanese archipelago, causing record-breaking rainfall, flooding, and landslides across Kyushu and the Kanto region on Thursday [1].
The convergence of these tropical systems with an active Meiyu plum-rain front creates a high risk of long-rain-accumulation disasters. This weather pattern can saturate soil over extended periods, significantly increasing the likelihood of catastrophic landslides and urban flooding.
In Kyushu, the impact has already been severe. Rainfall in Goto City exceeded 500 mm, setting a historic record for a 72-hour total [1]. In Omuta City, floodwaters rose to knee-depth, which immobilized vehicles and disrupted local transit [1]. Other areas experiencing heavy precipitation include Fukuoka-Yame and Saga-Takeo [1].
While the most immediate flooding is concentrated in the south, the Kanto region is also under warning. The interaction between the systems may lead to consecutive direct hits on the region, compounding the risk of infrastructure failure.
Logistical disruptions have already begun. All ANA and JAL flights to and from Okinawa were cancelled in anticipation of Typhoon 6 [3]. Separately, Typhoon 19 was tracked moving northwest at approximately 15 km per hour near Minami-Torishima as of June 22 [2].
Local authorities said residents should remain vigilant as the systems move. The combination of moist air from the two typhoons and the stationary rain front is expected to prolong the period of heavy precipitation [1].
“Rainfall in Goto City exceeded 500 mm, setting a historic record for a 72-hour total.”
The simultaneous presence of two tropical systems complicates meteorological forecasting and emergency response. When typhoons interact with a stationary rain front like the Meiyu, the resulting 'train effect' can lead to extreme precipitation totals that exceed the capacity of urban drainage and slope stabilization measures, making the risk of landslides more acute than during a single-storm event.
