A giant low so large it stretches from Antarctica to New Zealand is set to sweep in next week with gale-force winds and heavy rain.
The country is currently being blanketed by a high-pressure system, pushing inland temperatures over 10C above normal and into 'heatwave' criteria by Tuesday.
But when December arrives this large high over northern New Zealand moves off.
"This big area of low pressure will time itself just as this large area of high pressure over northern NZ slips away," WeatherWatch says.
"This will allow the low (which will fill the entire Southern Ocean from the lower part of NZ to Antarctica) to move in bringing strong, warm, west- to north-west winds early next week which could be up to gale-force at times.
"It's possible that this low will be so large it will take all of the first week of December to churn by New Zealand in the Southern Ocean."
Most of the heavy rain will hit the lower and western side of the South Island. Only a few showers look to make their way into the North Island where it's drier than it should be in several places for this time of year.
