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Tasmanian farmers face drought Southern Ocean wobble may offer climate clues Blocking high provides wet wealth for Tasmanian graziers
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Picture courtesy of the Australian Bureau of Meteorology Blocking high drives systems towards Tasmania This animated image, taken every six hours from July 4, 0532 GMT to July 12, 0532 GMT, shows a few more details than the smaller version. For starters, and this is just an aesthetic thing, check out the band of double low pressure cells to the west of Tasmania at the start of the animation and a very similar double low pressure cell to the east of the island at the end of the animation. Cool, eh? OK. Now, you can clearly see the front approaching Tasmania and splitting, with the northern portion traveling over northern Victoria, to combine with an upper level trough in the central Tasman to form a new low. As this new system travels south-west back towards Tasmania (under the influence of the New Zealand High), more moist air arrives from a north-west cloud band traveling across central Australia. However, the energy is not enough to create rain for drought-affected farmers on the Apple Isle, and the low spins south into the Southern Ocean. The New Zealand High continues to drive systems towards Tasmania, and when an ex-tropical cloud band forms to the east of Queensland, over Vanuatu, and combines with an upper trough traveling across New South Wales, a powerful double storm cell results. While the New Zealand High drives these two systems south west, deep into the Tasman sea, their location remains to far east to benefit Tasmania. © weather-wise.com 2000 |