Christchurch, New Zealand

Weather Underground Forecast for Tuesday, May 21, 2013.

Areas of wet weather continue in parts of eastern Asia on Tuesday as low pressure remains the dominant weather feature of the region. In the northeast, a low pressure system extending along the Heilongjiang coast and southeastern Russia shoreline will continue northward on Tuesday. This system will be fairly weak, allowing for small areas of light to moderate precipitation to develop mainly in southeastern Russia. Counter-clockwise flow around this system will allow moisture from the Sea of Japan to spread inland across northern Japan. This will translate into periods if increased cloud cover and areas of light to moderate scattered showers with isolated thunderstorms in the northern half of Honshu and in parts of Hokkaido. The brunt of precipitation and storms associated with this system will remain offshore in the western Pacific Ocean.

To the south, an upper trough of low pressure will remain stretched across the southeastern provinces of China and will usher a hot southwesterly airmass into the region. This setup will translate into widespread moderate to locally heavy rains and areas of squally thunderstorms in the provinces as the airmass pools along a stationary front extending across the region. This activity is also anticipated in Taiwan and will spread to Ryukyu island through Tuesday night.

For Australia, the storm system impacting Western Australia will move across the Northern Territory and South Australia as the associated trough of low pressure pushes across central Australia. Expect scattered showers and possible thunderstorms with the passing of this system. Areas near the South Australia coast should expect the heaviest amounts of precipitation as a surface low associated with this system skirts along the coast as it moves into the Great Australian Bight. by Tuesday night, this activity will begin to spread into the inland areas of Queensland and New South Wales.