Heavy rain and thunderstorms are hitting the north and west of the country on Thursday as an atmospheric river continues to cause torrential downpours.
The heavy rainfall has already caused a home in Taranaki to be evacuated, while in Nelson Tasman residents are being urged to "prepare for the worst".
It comes after the wild weather on Wednesday caused townships to be cut off and trapped people.
The weather on Thursday is already starting to cause disruptions.
One property was evacuated in Taranaki due to flooding and Civil Defence has not ruled out further evacuations.
Taranaki Civil Defence group controller Todd Velvin told AM drains can't cope with the intense downpours, which might cause more flooding throughout the day for other houses.
"At the moment, across Taranaki, we have seen quite an intense period of rain… It's still bucketing down outside but we haven't seen huge intensities that's affected any communities at this point in time," Velvin said.
Taranaki Civil Defence said regional council staff are monitoring river levels and at this stage, while they are higher than usual, there is nothing of concern to report.
"With all of the heavy rain, we have seen streams and rivers rising, and surface flooding has been reported in North Taranaki," the council said.
"In South and Central Taranaki, Council staff are clearing drains and continuing to assess the situation, but there are no known major incidents to report in these parts of the region."
Fire and Emergency New Zealand (FENZ) has received 21 weather-related callouts across the motu since midnight on Tuesday.
FENZ said they're continuing to closely monitor the weather warnings across the motu and are poised to send resources when and where they're needed.
In a statement, deputy national commander Brendan Nally said most weather-related callouts have been "minor incidents" in Northland, Bay of Plenty, Auckland, New Plymouth and Wellington.
FENZ plan to send specialist Urban Search and Rescue resources to Nelson on Thursday. They placed a USAR team in Northland on Wednesday.
"They are also ready to respond to Taranaki if needed," Nally said.
"It's important to be prepared, and to have these specialist resources on standby in the areas that will potentially experience the worst of this severe weather as is currently forecast for Northland, Taranaki, Tasman and Marlborough."
Nally warned power outages often occur during significant weather events and urged Kiwis to be prepared.
He encouraged those who do experience power outages to turn off the mains to ensure electricity doesn't cause a fire.
"Make sure you have your torches ready with full batteries," he said.
"Avoid using candles where possible as they are a fire risk. However, if you don't have any alternative lighting available, make sure you put them on a flat, heat-resistant surface, and blow them out when you leave a room."
Nally said now is the time to check smoke alarms are working too.
Meanwhile, Nelson Tasman Emergency Management is urging residents to prepare for up to 350mmm rainfall in some areas over just two days.
"These rainfall forecasts are sufficiently serious to be concerned. We should prepare for the worst and hope for the best," Nelson Mayor Nick Smith said in a statement.
"Make sure you have a plan and check on your neighbours or loved ones to be ready for whatever happens. If the weather hits during the day, think about how you will get home or pick up your children from school. We want everyone to be safe if this bad weather does hit."
Tasman Mayor Tim King said their rural support networks are already contacting farmers to make sure stock is safely out of flood zones.
"For any tourists to our region, we strongly recommend they stay away from rivers, as they could rise rapidly depending on the intensity of the rain," King said.
It is also recommended that people avoid travelling during heavy rainfall and to keep the roads clear. This will allow first responders and emergency services to respond quickly if needed. Waka Kotahi will be providing updates on the State Highway network.
While in Auckland Ferry services across the Gulf Harbour have also been cancelled.
Fire and Emergency New Zealand (FENZ) is preparing and sending resources where they're needed as regions across the motu brace for severe weather. FENZ deputy national commander Brandan Nally said resources have been sent to Northland and more locations will be considered.
MetService said the area likely to experience the longest period of heavy rain is the north of the South Island.
"For Tasman, Nelson and western Marlborough, there is high confidence that warning amounts of rain will fall on Friday and Saturday," MetService said. "There is moderate confidence that warnings will extend into Sunday and low confidence that there will still need to be a warning on Monday, especially in the west."
MetService's weather watches include an orange heavy rain warning for Northland, Waitomo, northern Taranaki, Tongariro National Park, Horowhenua to Wellington, parts of Marlborough and parts of Nelson/Tasman.
The weather forecasting agency noted there is a possibility that some of the orange warnings for Northland, Taranaki, Marlborough and Nelson/Tasman may be upgraded to a Red Heavy Rain Warning on Thursday.
Heavy rain watches have been issued for western parts of Auckland and Waikato, Taumarunui, southern Taranaki, Taihape, northern Whanganui, parts of Tasman and Buller.
MetService is urging people are urged to stay up to date with forecasts.
