Move over Debbie: New cyclone warning for New Zealand

A grim week is in store for storm-battered New Zealand with more deluges set to drench the country and a threat of a tropical cyclone bearing down at Easter.

It may be a fine weekend but it will be short lived with weather models showing northern and central New Zealand in the firing line for days of heavy rain fuelled by moist sub-tropical air.

Hard on its heels a tropical cyclone, which is starting to form north-east of Vanuatu, may be headed to our shores in time for next weekend and the start of the school holidays.

Weatherwatch.co.nz is describing the week leading up to Easter as another serious week for the country with the potential for more significant rain and the risk of further slips and flooding.

Niwa meteorologist Ben Noll said the next storm was due to hit Tuesday and continue through the middle of the week.

He said it appeared to be remarkably similar to the previous "Tasman Tempest" storm that saw Auckland and Coromandel inundated by flooding.

"It's fairly similar to the last two but it is unclear where the heaviest rain is going to happen," said Noll.

"Yesterday models we look at show increasing rain across the country from late Tuesday through midweek.

"It's set up very similar to the Tasman Tempest and the last two large storms."

At this stage it was too soon to tell where the worst weather would happen and if already saturated areas would suffer another drenching.

But it was likely to bring big rains to parts of the country even threatening to repeat levels recorded during this week's phenomenal rainfall.

"I would say it's not out of the realm of possibility," said Noll. "Some places will see hefty amounts of rain but that depends on the tropical connection and intensity of the storm itself."

He said most of the North Island and upper and eastern parts of the South Island would be affected by next week's deluge. The storm would also usher in another week of sticky, high humidity.

Weatherwatch.co.nz forecasters warned while the storm was not as tropical as the remnants of Debbie it may still be packed with heavy rain and slow moving enough to cause flooding.

But the Easter forecast looked far more ominous with a second possible cyclone tracking directly towards New Zealand in what would be an extraordinary week of back-to-back storms.

Noll said they were keeping a close eye on the tropics where a disturbance north-east of Vanuatu was expected to form into a tropical cyclone.

Weatherwatch.co.nz said while it was too far out to lock in reliable computer models had picked these storms to form for several days now and there appeared to be a zone around New Zealand suitable for at least two of three lows to merge.