White said monitoring equipment was currently being installed and would enable the council to make more informed decisions for residents in both the primary and secondary evacuation zones.

Almost all of the upper North Island is under a severe weather alert, with 24 heavy rain and wind watches stretching from Auckland and Coromandel across to Taranaki. Northland, Bay of Plenty and the Tongariro National Park are under a heavy rain warning.

The thunderstorm watch is active from 9am on Friday and lasts throughout the day. MetService is urging residents to be wary of streams and rivers rising rapidly and to drive safely in hazardous conditions.

Civil Defence has told residents across the top of the North Island to take time today to prepare for the deluge by relocating livestock, checking drains and gutters and securing any loose outside furniture.

They highlighted the danger of previous storms from last month and warned residents not to be complacent when the wild weather begins.

Aucklanders heading to work tomorrow will find themselves travelling in rain. A heavy rain watch is in place from 6am for 12 hours, with possible thunderstorms throughout the day.

“Rainfall amounts may approach warning criteria and possibly exceed them about isolated areas, especially in localised downpours,” MetService reported on its website.

A strong wind watch will also come into effect for Northland at 4am and Auckland at 7am, lasting for eight hours.

A heavy rain watch will come into effect for the Coromandel Peninsula, Bay of Plenty and Waikato at 8am tomorrow and will remain for 12 hours.

Gale-force winds tipped to strike South Island

Meanwhile, MetService forecaster Mmathapelo Makgabutlane told the Herald strong, gale-force winds were forecast to pick up in the South Island today.

Some 100mm of rain had already fallen overnight in the far south and was still coming down.

“It will be most parts of the South Island, but those areas under strong wind watches may see some of the stronger winds,” Makgabutlane said.

A strong wind watch came into force for the Canterbury High Country from 7am today until 2am tomorrow.

Another strong wind watch is forecast for the Queenstown Lakes District, Central Otago and Clutha from 7am to 9pm.

A strong wind watch is already in force for Fiordland, Southland and Stewart Island/Rakiura until 7pm today.

Makgabutlane said the Westland ranges could experience wet weather today.

“Some of that rain is expected to spill over to the other side of the Alps,” she said.

A heavy rain warning is already in place for the Westland ranges until 4am tomorrow with 200-250mm of rain expected, especially about and south of the glaciers. Peak rates of 20 to 30mm/h are set to hit from midday today onwards, with thunderstorms possible.

A heavy rain watch is already in place for Fiordland north of Doubtful Sound until 9pm.

A heavy rain watch is forecast to come into force for the headwaters of the Otago lakes and rivers from 4pm today until 1am tomorrow.

“Expect 100 to 150mm of rain about the main divide, and 60 to 90mm within 15km farther east,” MetService said.

“Peak rates of 15 to 25mm/h expected about the divide. Thunderstorms possible. Freezing level 2800m, lowering to 2000m.”