Mandurah, Western Australia

Weather Underground Forecast for Thursday, June 20, 2013.

Tropical Storm Leepi will begin to take a northeastward track toward Kyushu on Thursday as it continues moving through the eastern East China Sea. Leepi will round a subtropical ridge and accelerate northeastward through the day with little change in strength as it becomes embedded in the prevailing westerlies. Favorable environmental conditions should allow the storm to remain at tropical storm strength maximum sustained winds of 60 mph and higher gusts. Interest in Kyushu should expect heavy rainfall, strong winds, thunderstorms, and dangerous surf conditions as his storm nears the southeastern corner of the island Thursday night. By Friday Leepi may see some weakening as it moves just south of Honshu in the western Pacific Ocean and encounters increasing vertical wind shear and cooler sea surface temperatures. For more information on Tropical Storm Leepi, please visit http://ww.wunderground.com/tropical.

Meanwhile, unsettled weather will continue across much of southern Japan on Thursday as a frontal boundary associated with a low pressure system located northeast of the islands in the western Pacific Ocean remains nearly stationary as it reaches across Shikoku and East China Sea to the Shanghai area. Ample moisture from the south will pool along this boundary, allowing for another round of widely scattered light to moderate rain showers and areas of thunderstorms to develop along and near the boundary in parts of northern Kyushu, Shikoku, and southern Honshu. Shikoku will experience the brunt of this precipitation through the day, with areas of locally heavy rain possible and an increased risk of localized flooding. Tokushima will see a high near 73(F)/ 23(C) and continuous rain showers with totals near 1.7 inches/44.2mm during the day and 3.7 inches/93.2mm at night. Tokyo will also see more showers with a high near 77(F)/25(C) and rain totals near 0.7 inches/17.3 mm during the day and 1.1 inches/28.7 mm possible by night. Meanwhile, increased cloud cover and chances of light precipitation are anticipated near the tail of this disturbance in Shanghai.

As this disturbance soaks southern Japan, another low pressure system centered over Jilin and Heilongjiang will support light scattered showers with isolated areas of moderate precipitation in northeastern China and parts of North Korea. This activity should wane through Thursday night.

To the south, hot and muggy conditions continue across the southeastern provinces of China with isolated showers forecast to pop up across the area through the day.

For Australia, showers will begin to wane along much of the New South Wales and Victoria coasts on Thursday as low pressure continues eastward across New Zealand and high pressure noses in over Tasmania. This high will span across Victoria and New South Wales with a drier airmass and slightly cooler temperatures, while onshore winds maintain increased cloud cover and chances of showers to areas from Sydney through Brisbane. Meanwhile, a trough of low pressure and associated cold front will move into the Great Australian Bight with showers and increased winds. This activity is expected to clip the coast of South Australia by Thursday night, reaching Adelaide by Friday.