VICTORIA has been lashed by the tail of cyclone Yasi, producing severe storms and torrential rain.
The moist air from Yasi, downgraded from a cyclone to a tropical low after its winds eased below gale force, was dragged south in an arc from Queensland's north-west, through Alice Springs and as far south as Melbourne.
A large cold front heading north cooled the warm monsoonal air and caused huge cloudbursts that dumped up to 200 millimetres of rain in just two hours over Melbourne and regional Victoria.
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Moisture remaining from cyclone Anthony was also hanging over the state and contributed to the deluge.
Bureau of Meteorology senior forecaster Stephen King said the weather was unusual for Melbourne.
''We have had extremely high moisture levels in the air from both ex-cyclone Anthony and Yasi … Then we had a [cold] trough yesterday that triggered the thunderstorm activity,'' Mr King said.
''This sort of rain coming from the tropics, you get it in Sydney and Brisbane, it's not that unusual, but to get it this far south is probably quite rare.''
Melbourne's south-eastern suburbs were among the worst-affected areas. Lyndhurst recorded 180 millimetres of rain in the 24 hours to 9am yesterday.
Mildura, in the state's north-west, recorded 142 millimetres - the town's highest daily rainfall total on record.
Ex-cyclone Yasi was yesterday hovering over the Northern Territory, about 430 kilometres south-west of Mount Isa, causing heavy rain in far west Queensland. It is expected to continue to spread moisture into south-eastern Australia today, but its influence will diminish by tomorrow.
While the wild weather across Australia in the past two weeks may feel like an end-of-days movie, experts say it is the product of bad luck and normal long-term weather patterns.
Environmental scientist Stewart Franks at the University of Newcastle said cyclonic activity and recent major flooding in Australia's eastern states were the result of La Nina activity, which has been intensified by Pacific Decadal Oscillation, or low-frequency cooling in the mid-latitudes. Associate Professor Franks rejected the idea that category-5 cyclone Yasi was unprecedented. He said cyclone Mahina in north Queensland in 1899 was stronger.
Climate change groups have argued that record-high sea temperatures in the Coral Sea, while not responsible for the cyclone, have likely contributed to its intensity.
''We have had a warming in the atmosphere, and a demonstrable warming in the oceans, and that extra energy drives intensification of those [cyclone] systems,'' said Climate Institute chief executive John Connor.
''On the eve of the second anniversary of the bushfires, where we had unprecedented fire weather conditions, the point that I've been trying to make is that if you want a picture of a hostile and costly environment, we've been having this in spades over the past few years.''
But Professor Franks said the half-a-degree increase in water temperature in Australia's tropics was far too small to intensify cyclones.
He said the current La Nina cycle, which began during the New South Wales storms in 2007, could continue for the next 10 to 30 years.
He said the eastern states could expect a continuation of wetter conditions in the next few months, and that in the tropics there was a chance of more cyclones.
But Victoria will at least have a chance to dry out, with rain expected to clear today before a fine week.
The moist air from Yasi, downgraded from a cyclone to a tropical low after its winds eased below gale force, was dragged south in an arc from Queensland's north-west, through Alice Springs and as far south as Melbourne.
A large cold front heading north cooled the warm monsoonal air and caused huge cloudbursts that dumped up to 200 millimetres of rain in just two hours over Melbourne and regional Victoria.
Advertisement: Story continues below
Moisture remaining from cyclone Anthony was also hanging over the state and contributed to the deluge.
Bureau of Meteorology senior forecaster Stephen King said the weather was unusual for Melbourne.
''We have had extremely high moisture levels in the air from both ex-cyclone Anthony and Yasi … Then we had a [cold] trough yesterday that triggered the thunderstorm activity,'' Mr King said.
''This sort of rain coming from the tropics, you get it in Sydney and Brisbane, it's not that unusual, but to get it this far south is probably quite rare.''
Melbourne's south-eastern suburbs were among the worst-affected areas. Lyndhurst recorded 180 millimetres of rain in the 24 hours to 9am yesterday.
Mildura, in the state's north-west, recorded 142 millimetres - the town's highest daily rainfall total on record.
Ex-cyclone Yasi was yesterday hovering over the Northern Territory, about 430 kilometres south-west of Mount Isa, causing heavy rain in far west Queensland. It is expected to continue to spread moisture into south-eastern Australia today, but its influence will diminish by tomorrow.
While the wild weather across Australia in the past two weeks may feel like an end-of-days movie, experts say it is the product of bad luck and normal long-term weather patterns.
Environmental scientist Stewart Franks at the University of Newcastle said cyclonic activity and recent major flooding in Australia's eastern states were the result of La Nina activity, which has been intensified by Pacific Decadal Oscillation, or low-frequency cooling in the mid-latitudes. Associate Professor Franks rejected the idea that category-5 cyclone Yasi was unprecedented. He said cyclone Mahina in north Queensland in 1899 was stronger.
Climate change groups have argued that record-high sea temperatures in the Coral Sea, while not responsible for the cyclone, have likely contributed to its intensity.
''We have had a warming in the atmosphere, and a demonstrable warming in the oceans, and that extra energy drives intensification of those [cyclone] systems,'' said Climate Institute chief executive John Connor.
''On the eve of the second anniversary of the bushfires, where we had unprecedented fire weather conditions, the point that I've been trying to make is that if you want a picture of a hostile and costly environment, we've been having this in spades over the past few years.''
But Professor Franks said the half-a-degree increase in water temperature in Australia's tropics was far too small to intensify cyclones.
He said the current La Nina cycle, which began during the New South Wales storms in 2007, could continue for the next 10 to 30 years.
He said the eastern states could expect a continuation of wetter conditions in the next few months, and that in the tropics there was a chance of more cyclones.
But Victoria will at least have a chance to dry out, with rain expected to clear today before a fine week.
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