After losing wind intensity and spinning just off the coast of China over the East China Sea for several days earlier this week, AccuWeather forecasters say Chanthu is making its final impact to eastern Asia as it tracks across Japan.
Chanthu has amassed quite the track record and has certainly made its mark since first forming in the West Pacific basin last week. Chanthu's intensity peaked late last week when it became only the second super typhoon of the season after undergoing rapid intensification. The typhoon went on to unleash flooding rain and damaging winds across portions of the Philippines and Taiwan before slowing down and targeting China's eastern coast this week.
As of Saturday afternoon, local time, the center of Tropical Storm Chanthu was located just south of Hamamatsu, Japan. Chanthu was moving to the east at 19 mph (30 km/h), according to the Japan Meteorological Agency (JMA). Chanthu had become an area of low pressure with minimal winds.
"Chanthu will continue to push eastward and spread heavy rain that could produce flooding in parts of Japan on Saturday, local time," AccuWeather Senior Meteorologist Jason Nicholls explained.
As Chanthu passed southern South Korea, it brought wind gusts to near 50 mph (80 km/h) and 8.54 inches (217 mm) of rain to Jeju Island, South Korea, on Thursday.
Intense rainfall followed the storm as it pushed to the east with 14.25 inches (362 mm) of rain falling in Kubokawa, Japan, on Friday. Most of this fell within seven hours.
"The wind threat should ease into the weekend, but the flooding risk will remain high," Nicholls said.
Periods of heavy, tropical rainfall are forecast to drop more than half a foot (more than 150 mm) of rain across parts of Japan on Saturday.
Low-lying and poor drainage areas will be most susceptible to flooding at the onset of Chanthu's rainfall, but as more rain continues to fall, area waterways will begin to swell. In addition, any mountainous terrain in the path of Chanthu's heaviest rainfall will be at risk for mudslides due to oversaturated soil.
As Chanthu tracks eastward through Saturday, widespread wind gusts of 40-60 mph (60-100 km/h) will be common across Kyushu, Shikoku and southern and eastern Honshu. Higher wind gusts can occur across the south coast of Kyushu and southern Honshu.
While widespread damage is not expected, these winds could produce isolated power outages and down some tree branches.
Due to the threat of flooding and mudslides as well as locally damaging wind gusts, Chanthu is a 1 on the AccuWeather RealImpact™ Scale for Typhoons in Japan. The AccuWeather RealImpact™ Scale is a 6-point scale with ratings of less than one and 1 to 5.
In contrast to the Saffir-Simpson Hurricane Wind Scale, which classifies storms by wind speed only, the AccuWeather RealImpact™ Scale is based on a broad range of important factors. In order to better communicate a more comprehensive representation of the potential impact of a storm to lives and livelihoods, the scale covers not only wind speed but also flooding rain, storm surge and economic damage and loss.
After moving across portions of Japan on Saturday, AccuWeather forecasters say Chanthu is set to push into the North Pacific Ocean early next week. It is over the open waters of the Pacific that the system will enter more hostile conditions for development and likely dissipate.
What's left of Chanthu could be seen over Japan late Friday local time on AccuWeather's Enhanced RealVue™ Satellite.
Prior to impacting Japan, Chanthu already had a long history of destruction across eastern Asia, including in the Philippines, Taiwan and eastern China.
At least one location in Zhoushan City's Dinghai District received 26.1 inches of rain (662 mm) from Chanthu. Elsewhere, more than 300,000 people in Shanghai were evacuated due to Chanthu's impacts, according to state-affiliated media.
The storm wreaked havoc earlier this week when transportation services including flights and trains were suspended in Shanghai, The Associated Press reported. Schools around the city were also closed on Monday due to the storm. Most of the transportation services were restored by Tuesday.
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