A weather system thousands of kilometres wide is driving its way towards New Zealand.
According to Weatherwatch, the "enormous" high pressure belt will come across Australia, move east and likely cover New Zealand by next weekend.
"In the weather world we don't say weather systems are 'enormous' very often – but this high pressure belt is. For a time next week it will roughly stretch 7000km across - to give some perspective Australia is almost 4000km from west to east and NZ is only 1600km from north to south."
Weather forecaster Philip Duncan said that on Monday it will encompass the distance between Perth and the international date line.
"Several thousand kilometres across. New Zealand is only 1600km north to south. This is a huge system moving through and it is going to dominate our weather."
It's expected the system will take all of next week to track from Adelaide to Sydney and across the Tasman.
"Put simply - next week leans drier than average in many places (with showers here and there) and cooler W to SW winds will be colder the further south you go," Weatherwatch says.
"Next weekend the high should cross NZ bringing lighter winds and a newly forming easterly flow for northerners."
Graphics from Weatherwatch show the system completely encompassing New Zealand from next Saturday.
In ten days the high departs New Zealand to the east and "this changes things".
"We expect rainfall levels to be closer to normal for northern NZ this month, that despite a drier than normal week on the way from tomorrow, Saturday, onwards.
"We may see more evidence of this wetter weather as this high pressure system departs our shores pulling down northerlies from the sub-tropics into both islands and potentially sparking another rainmaker for the north and west out in the Tasman Sea."
The forecaster says it's too far out to know exactly how things will develop but it is "one big high with quite an interesting weather tale".
