Philippine Sea: Typhoon Khanun tracking west-northwestward southeast of Okinawa, Japan, as of late Aug. 1 /update 5

Event

Typhoon Khanun is tracking west-northwestward in the northwestern Philippine Sea late Aug. 1. As of 21:00 JST, the system's center of circulation was approximately 133 km (82 miles) south of Kadena Air Base, Okinawa, Japan.

Forecast models indicate that the storm will weaken slightly as it continues west-northwestward and passes between Okinawa main island and Miyako Island early Aug. 2, before it enters the East China Sea and continues west-northwestwards through Aug. 3. The storm is likely to make a sharp turn to track northeastward early Aug. 4 and weaken further into a tropical storm as it approaches the Amami Islands, Kagoshima Prefecture through Aug. 6. Uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of late Aug. 1, the Japan Meteorological Agency (JMA) has issued purple (the highest level on a three-tier scale) storm surge warnings and red storm and high wave warnings across much of Okinawa Prefecture and the Amami region of Kagoshima Prefecture. The JMA has advised residents in the Okinawa and Amami regions to move into a sturdy building and stay away from windows indoors, be extremely vigilant against strong winds, and be careful of high waves. Winds gusting up to 234 kph (145 mph) are possible in parts of Okinawa Prefecture over the coming days, as well as gusts up to 126 kph (78 mph) in the Amami Islands. Rainfall totals of 20 cm (8 inches) are forecast in Okinawa and 12 cm (5 inches) in the Amami Islands late Aug. 1-2 and further amounts of 30 cm (12 inches) in Okinawa and 10-15 cm (4-6 inches) in Amami are expected late Aug. 2-3. Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

Authorities in Okinawa Prefectures have issued evacuation orders to more than 750,000 people across Itoman, Miyakojima, Nago, Naha, Nanjo, Okinawa, Tomigusuku, and Uruma cities, Kin, Motobu, Nishihara, Yaese, and Yonabaru towns, and Ginoza, Higashi, Kunigami, and Ogimi villages as of late Aug. 1, including more than 300,000 people in Naha City. According to the Okinawa Electric Power Company, more than 170,000 households were without power across Okinawa Prefecture as of 22:00 Aug. 1.

Japan Airlines (JL) canceled all flights at Naha (OKA), Kikai (KKX), Amami (ASJ), Tokunoshima (TKN), Okinoerabu (OKE), Yoron (RNJ), Kitadaito (KTD), Minamidaito (MMD), Kumejima (UEO), Miyako (MMY), Tarama (TRA), Ishigaki (ISG), and Yonaguni (OGN) airports Aug. 1-2. All Nippon Airways (NH) canceled all flights at Naha (OKA), Miyako (MMY), and Ishigaki (ISG) airports Aug. 1-2 and some flights at the affected airports early Aug. 3. Other airlines have also canceled hundreds of flights to Okinawa and Kagoshima prefectures. Further flight cancellations are possible as the storm approaches and weather conditions deteriorate. Authorities have also canceled many ferries across the prefectures.

Sustained heavy rainfall could trigger flooding in low-lying areas and those with easily overwhelmed drainage systems. If weather conditions prove hazardous, localized evacuations, flash flooding, and landslides are possible.

The inclement weather could trigger localized business, transport, and utility disruptions and render some bridges or roadways impassable. Additional flight disruptions at regional airports and temporary closures of ports are also possible. Stagnant pools of water during and after flooding increase insect- and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.

Advice

Activate contingency plans in areas where officials forecast tropical storm conditions. Heed any evacuation orders that may be issued. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the potential for severe flooding and storm surge. Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents and necessary medications in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil-water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming weeks.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

Joint Typhoon Warning Center (JTWC)
Japan Meteorological Agency (JMA)
Taiwan Central Weather Bureau
China Meteorological Administration
Korea Meteorological Administration