Japan braces for flooding rain as Mawar continues destructive path

Mawar, once a formidable typhoon that caused destruction across Guam last week, continued its slow churn in the northern Philippine Sea, near Japan's Ryukyu Islands, as of late Thursday evening, local time. AccuWeather meteorologists say the storm will continue to lose wind intensity into the weekend, but its interaction with a non-tropical system over Japan can lead to a tropical deluge across the country.

Mawar, known as Betty in the Philippines, was still packing maximum sustained winds equivalent to that of a tropical storm (39 to 73 mph, or 63-118 km/h) on the Saffir-Simpson Hurricane Wind Scale at midweek.

Although the storm never directly impacted the Philippines or Taiwan, both countries felt impacts earlier this week. At the beginning of the week, officials in the northern Philippines ordered the evacuation of thousands of people, while businesses and schools were shuttered, according to The Associated Press. Meanwhile, rough seas generated by Mawar swept four people out to sea along the eastern coast of Taiwan on Sunday, with one person reported dead, according to Taiwan News.

Mawar was once an even more powerful typhoon over the open waters of the Philippine Sea, following its path close to Guam, with winds equivalent to that of a Category 5 hurricane (at least 157 mph, or 252 km/h) early this past weekend. That wind intensity made the typhoon the strongest storm on the planet so far this year.

"Mawar will gradually lose wind intensity as it drifts slowly northward into an area of cooler sea-surface temperatures over the next couple of days," said AccuWeather Lead International Forecaster Jason Nicholls. The typhoon will eventually accelerate northeastward this weekend.

GET THE FREE ACCUWEATHER APP

Have the app? Unlock AccuWeather Alerts™ with Premium+

AccuWeather meteorologists say this path will put Japan's Ryukyu Islands and mainland in line to receive strong winds and heavy rain from Mawar, despite its continued loss in wind intensity.

"The heaviest rain and strongest winds should occur over the southern Ryukyu Islands into Thursday night as the center makes its closest pass to the islands. Rainfall over the southern Ryukyu Islands will be 4-8 inches (100-200 mm), with an AccuWeather Local StormMaxof 24 inches (600 mm)," Nicholls said.

Rain is expected to be enhanced across Japan as Mawar collides with a non-tropical system over the country.

"Rain, some heavy, and a risk of flooding are possible in the northern Ryukyu Islands and parts of southern Japan later Thursday and Friday, local time, as a front interacts with Mawar," Nicholls said.

The worst of the rain is expected to reach Tokyo from Thursday night to Friday evening, local time. Travel disruptions are likely as a result of the downpours.

Although Mawar is a tropical storm at this point in its life cycle with the center of the storm staying south of mainland Japan, AccuWeather forecasters say locally damaging winds cannot be ruled out across southern Japan.

Despite slamming Guam with 120-mph (195 km/h) winds and 2 feet of rain last Wednesday, May 24, Mawar has yet to make a direct landfall anywhere along its path. Continuing that somewhat fortunate trend, the typhoon did not make landfall in the Philippines and Taiwan early this week despite coming dangerously close. That streak may end with Mawar's path close to Japan's Ryukyu Islands later this week.

AccuWeather meteorologists are closely monitoring whether the curving tropical system could eventually have a bearing on the weather and temperature trends across the contiguous United States in early June.

Want next-level safety, ad-free? Unlock advanced, hyperlocal severe weather alerts when you subscribe to Premium+ on the AccuWeather app. AccuWeather Alerts are prompted by our expert meteorologists who monitor and analyze dangerous weather risks 24/7 to keep you and your family safer.