Just over two weeks have elapsed since Typhoon Haishen battered portions of Japan and the Korean Peninsula with heavy rain and damaging winds. After a needed respite from tropical activity, a new tropical threat for Japan developed in the Western Pacific Ocean basin early this week.On Monday afternoon, local time, a tropical depression churning over the Philippine Sea strengthened into Tropical Storm Dolphin, according to the Japan Meteorological Agency.As of Monday evening, local time, Tropical Storm Dolphin is located about 1,000 km (621 miles) south of Osaka, Japan. Dolphin will continue to track generally northward over the Philippine Sea and intensify some over the next day or two before impacts can be felt along the Japanese coast. Tropical Storm Dolphin churns over the Philippine Sea Monday evening, local time. (CIRA/RAMMB) Dolphin will likely be able to intensify into a severe tropical storm sometime on Tuesday before it encounters stronger wind shear over Japan. Depending on how long Dolphin can avoid this stronger wind shear, it may even be able to achieve sustained wind speeds that will place it on par with a Category 1 hurricane on the Saffir-Simpson Hurricane Wind Scale in the Atlantic and East Pacific basins."As Dolphin tracks northward, it will spread rain, some heavy, across southern Japan Tuesday night or Wednesday, local time, with rain continuing across southern and eastern Japan into Saturday," said Jason Nicholls, AccuWeather's lead international forecaster.While rain from Dolphin will spread over much of the country this week, the heaviest will take aim at portions of southern and eastern Honshu. Beginning Tuesday night or early Wednesday and continuing for much of the week, Dolphin will unleash heavy downpours over portions of the Kansai, Chūbu, Kanto and Tōhoku regions. Across these areas, rainfall totals of 100-200 mm (4-8 inches) will be common. Heavy rain can lead to flash flooding and can increase the potential for dangerous mudslides.The exact track of Dolphin as it nears Japan at midweek will depend on several factors. One such factor will be a non-tropical system expected to move over northeastern China early this week. This non-tropical system may act to pull Dolphin more to the north as it approaches Japan, rather than allowing it to make a sharp turn to the east and closely parallel the coast."Tropical Storm Dolphin is expected to strike southern Japan later Thursday and Thursday night," Nicholls added. Depending on the strength of the influence the non-tropical system exerts on Dolphin, the track of the storm near and after landfall may vary.At this time, Dolphin's most likely track suggests the potential for landfall exists somewhere along the southeastern Chūbu region. An AccuWeather Local StormMax™ of 250 mm (10 inches) will possible for areas that end up trapped under persistent, heavy downpours near where Dolphin makes landfall.With this potential landfall point, Dolphin will likely go on to adopt a more northeasterly track and pass near or directly over Tokyo as it unleashes heavy rain. However, if the influence of the non-tropical system is strong enough, Dolphin may shift and take a more northerly track after landfall, taking it into the Sea of Japan.In addition to rain, damaging wind gusts will also spread over portions of Japan as Dolphin approaches the coast. An AccuWeather Local StormMax™ of 80 mph can occur near where Dolphin makes landfall. Winds of this strength can cause damage to trees, power lines and any poorly constructed structures. Rough seas will also become a concern as Dolphin tracks near Japan.CLICK HERE FOR THE FREE ACCUWEATHER APPThe heaviest rain will then shift north into Hokkaido later this week as Dolphin continues its general northward motion. Here, a rainfall amount of 50-100 mm (2-4 inches) will be common.To end the week, high pressure will begin to build across the Korean Peninsula and expand eastward over portions of Japan. High pressure will continue to build over much of Japan late this weekend and persist into early next week, allowing the area a chance to dry out.Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.