Another cyclone warning has been issued for New Zealand as a disturbing weather pattern builds up in the Pacific.

Weather Watch says this could cause a "direct hit to New Zealand in Northland and Auckland" and warns it's forecast to be a "much bigger storm than Fehi".

"A tropical cyclone is expected to form in the next day or so in the Fiji / Tonga area," Weather Watch says.

"According to reliable computer modelling the storm will intensify as it drifts westwards and may become 'severe' in the tropics - then starts to curve southwards by next Friday/Saturday."