Tropical season is in full swing in the West Pacific, as evidenced by the three tropical storms currently spinning in the basin.
“The biggest threat to the Japanese mainland will be the storm farthest away currently, as Tropical Storm Mindulle will approach southeast Honshu early this week,” AccuWeather Meteorologist Eric Leister said.
Mindulle will maintain its strength as a tropical storm as it moves through warm ocean waters and battles upper-level winds.
Eastern Honshu will begin to feel impacts from Mindulle on Monday morning, local time. Conditions will worsen as the storm makes landfall southwest of Tokyo Monday night into Tuesday.
The main threats from Mindulle will be flooding rainfall, with widespread amounts of 100 to 150 mm (3 to 6 inches) expected from Tokyo to Sendai and up to Sapporo. Locally higher amounts are possible from the heavier rain bands.
Residents should be on alert for the potential for mudslides and take precautions when driving in areas that may be flooded.
The strongest wind gusts will be along coastal regions.
There are two other tropical systems in the vicinity of Japan.
Tropical Storm Kompasu will continue on a northward track through Monday.
“Kompasu made landfall Sunday night local time in southern Hokkaido. The storm will bring locally heavy rainfall and gusty winds to northern Honshu and eastern Hokkaido into Monday,” AccuWeather Meteorologist Eric Leister said.
This first round of flooding from Kompasu will set the stage for an enhanced flood risk from Mindulle when it moves through late Monday into Tuesday.
The final storm, Tropical Storm Lionrock, is located several hundred kilometers southwest of Tokyo and is expected to drift slowly to the west-southwest before stalling near the Ryukyu Islands.
Tropical Storm Lionrock could intensify into a typhoon next week and bring flooding rain and damaging winds to the Ryukyu Islands.