Tropical Storm Jangmi swept across Japan in early June, bringing heavy rainfall, powerful winds, and flooding that disrupted transportation, left hundreds of thousands without power, and forced evacuations across multiple prefectures.
The storm made its strongest impact in the Tokyo metropolitan area and surrounding regions. In Kanagawa Prefecture, a road intersection in Kawasaki’s Saiwai Ward flooded with water reaching depths of 30 centimeters. A section of a national highway in Tokyo’s Ota Ward was also inundated. Flood alerts were issued across Honshu as the storm moved inland.
Maximum sustained winds reached 30 meters per second, with gusts climbing to 45 meters per second. The name Jangmi, contributed by South Korea, means rose in Korean. The meteorological significance belied any poetic beauty — the system dumped torrential rain across the region for hours.
Transportation ground to a halt. Railways in the Tokyo metropolitan area saw widespread cancellations and delays. Airlines canceled hundreds of flights, including services to and from Haneda Airport. The disruptions stranded travelers and complicated logistics networks already stretched thin in the region.
More than 12,000 homes in the Kanto-Koshin region lost power by Wednesday evening. Utility companies worked through the night to restore service, but full restoration took days. Supermarkets with spoiled inventory and hospitals running on backup power illustrated the cascading effects of widespread outages.
Evacuation advisories were issued for over 800,000 residents. Most were precautionary, issued before rainfall and wind speeds peaked. But they reflected the genuine risk flooding poses in densely populated areas where drainage systems are already taxed during heavy storms.
The storm was part of the broader typhoon and tropical storm season across the western Pacific. Japan experiences several such systems annually. Jangmi’s particular track and intensity made it worse than average but not unprecedented. Improved building codes and early warning systems have reduced casualties in recent decades, though economic damage from flooding and wind remains substantial.
