[Bill Douglas]

It's New Zealand's fault.

My theory. NZ has warmed up so much we get a large high pressure sitting over the country. Small high pressure systems move away in a day or two, but these large ones stay for a week or more. this creates a low pressure system that stalls and it routes hot humid air from the Samoa area straight onto Australia's east coast where it condenses into rain.. Two weeks of this and the place is under water.

It didn't use to happen.