Philippine Sea: Typhoon Khanun tracking northwestward southeast of Okinawa, Japan, as of early July 31 /update 3

Event

Typhoon Khanun is tracking northwestward in the central Philippine Sea early July 31. As of 12:00 JST, the system's center of circulation was approximately 656 km (407 miles) southeast of Kadena Air Base, Okinawa, Japan.

Forecast models indicate that the storm will strengthen further as it continues northwestward across the Philippine Sea through Aug. 1. Khanun is forecast to pass between Okinawa main island and Miyako Island early Aug. 2 before weakening as it enters the East China Sea. The storm is likely to weaken further as it turns to track north-northwestwards then northeastward in the central East China Sea through early Aug. 5. Uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

As of early July 31, the Japan Meteorological Agency (JMA) has issued orange (middle level on a three-tier scale) high wave warnings across the Daitojima Region and orange storm surge advisories across the northern main island of Okinawa. Yellow storm surge, thunderstorm, high wave, and gale advisories are in place across the rest of the Ryukyu Islands. The JMA has advised residents in the Okinawa and Amami regions to refrain from going outside unless absolutely necessary, stay away from windows indoors, and be extremely vigilant against storms July 31-Aug. 1. Heavy rainfall of 15 cm (6 inches) is forecast across the Amami region of Kagoshima Prefecture, while 10 cm (4 inches) of rainfall is likely across Okinawa Prefecture through early Aug. 1. Authorities will likely issue new warnings or update existing advisories throughout the system's progression in the coming days.

Japan Airlines (JL) canceled 67 flights and All Nippon Airways (NH) canceled 124 flights across Okinawa and Kagoshima prefectures July 31. Other airlines have also canceled flights to the prefectures. Further flight cancellations are possible as the storm approaches and weather conditions deteriorate.

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. 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