Tropical Storm Malou will target Japan with heavy rain and strong winds this week.
Malou is expected to become the seventh tropical system to make landfall in Japan as it crosses eastern Honshu near Tokyo on Thursday.
While some strengthening is expected, Malou is forecast to remain a tropical storm through Friday as it skirts along Japan's eastern coastline.
Significant flooding rainfall could trigger mudslides and create widespread travel delays.
Rainfall of 50-100 mm (2-4 inches) will be common across eastern Honshu with local amounts exceeding 150 mm (6 inches).
The strongest winds will unfold near the coast and also include much of Greater Tokyo. Gusts over 80 km/h (50 mph) are possible.
The worst conditions for Tokyo will be Wednesday night through midday Thursday. While the track of the storm is expected to be near or east of Tokyo, the heaviest rain is expected in higher terrain areas to the north and west of the city. These regions will have the highest risk for mudslides.
The combination of flooding rain, strong winds and mudslides could create travel chaos with possible flight delays, train cancelations and slow travel in and around the city, especially during the morning commute on Thursday.
"Locations from Kochi to Tokyo and Sendai have received above-normal rainfall in August," AccuWeather Meteorologist Adam Douty said.
"Because of the recent wet pattern, additional rainfall from Malou could lead to flooding more quickly than normal," added Douty.
Malou will continue tracking northeast into Friday, taking the tropical storm to the east of Hokkaido.
Impacts to Hokkaido will be limited to light rainfall and rough seas with some threat for coastal flooding in the typically prone areas at high tide.
A couple of largely dry days are expected across Japan following Malou. However, additional tropical threats could develop as early as the beginning of next week.