"By Friday the low just off Sydney's coastline will weaken significantly - as mostly dry weather remains over New Zealand, however with the high drifting further away to our east a northerly quarter wind flow will develop over the country."
This means a warm weekend for many regions with winds from the north west to north east for many regions. But by Sunday the leftovers of the Australian storm will be reforming over the southern Tasman Sea and begin to loom over New Zealand..
A new, larger, low will deepen rapidly on Sunday evening and into Monday morning as it starts to cross New Zealand.
"Some parts of New Zealand will have a wet and windy public holiday on Monday - with the low affecting most of the country at some point across the day," Mr Duncan said.
"Like New South Wales the low will take a few days to clear New Zealand - however it will be a different low by the time it reaches New Zealand with any potential severe weather coming in different forms."
There is a chance of isolated thunderstorms across Monday and Tuesday. Heavy rain is also possible in western areas, he said, with strong to gale force winds in some areas.
"A repeat of the major damage in parts of New South Wales is not expected in New Zealand. However the low will have enough energy to create localised damaging weather in some parts of our country."