Japan issues disaster warnings as line-shaped rainbands trigger floods and power outages

The Japan Meteorological Agency issued a meteorological disaster warning at 09:02 local time on 3 June 2026 for the development of a line-shaped precipitation band in eastern Kanagawa Prefecture. Authorities warned that the phenomenon, characterised by a line of developed cumulonimbus clouds, poses a risk of life-threatening landslides and flooding. This alert was part of a broader severe weather pattern associated with Typhoon No. 6, which has caused river water levels to rise across the Kanto region.

Concurrent alerts extended to neighbouring jurisdictions, reflecting the widespread nature of the storm system. A Level 4 heavy rain danger warning was issued for Kamogawa City in Chiba Prefecture, urging strict caution against flooding and river overflow. In Tokyo, evacuation orders were enacted for the Kanda River basin in Toshima Ward due to the risk of overflow and inundation. Additional measures included a Level 4 heavy rain danger warning for Shinagawa Ward and evacuation information for the elderly in Bunkyo Ward, citing risks of inland flooding.

The Japan Meteorological Agency also issued an "imminent prediction" for line-shaped precipitation bands in southern Wakayama, southern Mie, and southern Tokushima prefectures earlier in the morning. Operational disruptions were already evident in Shikoku, where approximately 17,000 households experienced power outages following the development of rainbands in that region. The agency confirmed the development of the band in southern Tokushima Prefecture shortly after 01:21 am on 3 June.

Transport networks faced significant interruptions as authorities prioritised safety. Hokuriku Shinkansen services between Nagano and Kanazawa were suspended, and flight cancellations were reported. Earlier in the morning, evacuation orders had already been issued for parts of Yokohama’s Totsuka Ward and Yokosuka City in Kanagawa Prefecture, with local authorities noting the risk of flooding in the Hirado Nagaya River in Yokohama.

Further evacuation information was disseminated across the region to mitigate risks. A Level 3 evacuation information for the elderly was issued for Kawagoe City in Saitama Prefecture, citing risks of inland flooding. The coordinated response from the Japan Meteorological Agency and local governments highlights the severity of the weather event, which continues to threaten infrastructure and public safety across multiple prefectures.