Japan: Storm Haishen upgraded to super typhoon on September 4

Event

The US Joint Typhoon Warning Center (JTWC) reported on Friday, September 4, that storm Haishen had strengthened into a super typhoon in the Philippines Sea, 600 km (370 miles) southeast of Okinawa. Maximum sustained winds of 250 kph (155 mph) have been reported, making Haishen equivalent to a category 4 hurricane. Forecasters have stated that they believe the storm to have peaked, and it is expected to gradually lose intensity as it moves north-northwest. Heavy rainfall has been reported in islands south of mainland Japan, and businesses and factories have reportedly been shut down in the regions of Kyushu and Chugoku in preparation for the storm. Haishen is expected to pass west of Kyushu before making landfall in South Korea late on Sunday, September 6, or early on Monday, September 7.

Strong winds, heavy rainfall, and associated flooding and landslides are expected in southern Japan over the coming days. Disruption to transportation, business, and utilities is likely.

Context

The typhoon season lasts from May to October, whilst most storm systems form between July and September. In general, storms can bring heavy downpours and strong winds as well as trigger storm surges that threaten human populations and infrastructure. Secondary effects include riverine floods and landslides, both of which can result in human casualties and mass evacuations, as well as travel and service disruptions. Although storm systems usually affect southern Japan, other parts of the country are also vulnerable to these hazards.

Advice

Those in the affected areas are advised to monitor local weather reports, avoid areas directly affected by flooding, confirm road conditions before setting out, and adhere to instructions issued by local authorities.