Heavy rain warnings and watches have been issued for large parts of the country. Photo: Supplied / MetService
The worst of the rain for the upper North Island is expected to hit during school drop-off and the morning commute.
It follows a night of heavy rain that pushed in from the North.
A severe rain warning was in place for Northland until 1pm on Friday, with more than a month's worth of rainfall set to hit the region in just a few days.
Metservice meteorologist Alec Holden said Auckland would be under a weather watch from 3am until 2pm on Friday.
"In the overnight period we are expecting to see a jump in rainfall in both Northland and Auckland as a large moist air stream passes over."
Holden said the worst of the rain in Auckland was expected to hit during school drop-off time and as many commuted to work on Friday morning.
He said there was a moderate chance rainfall amounts in Auckland would reach warning criteria.
Heads up!
— MetService (@MetService) April 3, 2025
☔️Auckland and Northland commuters! Expect rain tomorrow morning, which could lead to wet roads and slower traffic. Allow extra travel time, drive to the conditions, and don’t forget your umbrella!
Stay updated via your local council and on https://t.co/Yjbq0jgaoz pic.twitter.com/gh3gGC2OmA
Officials across the top of the South Island and the West Coast were also monitoring heavy rainfall into the night - brought to our shores by a deep low crossing the Tasman Sea.
Orange heavy rain warnings are in place for much of the country, with the heaviest rain expected in Tasman, north-west of Motueka.
Tasman District Council's environmental science group manager Rob Smith said the region could expect to see upwards of 500 millimetres of rain in total across Thursday and into Friday.
He said that wasn't an unusual amount of rain for the north-west of the region, including Golden Bay, but it was the shape of the weather system that was the issue.
"The way it's coming in with a low on one side and a high on the other side, if the high were to stop or the low were to sit there for longer, it is a bit of a conveyor belt and if we get any embedded cells we can get higher rainfall... if we were to get 30 millimetres for three hours in a row, it starts to change the nature of that flood risk."
Smith said major rivers in the district's north-west - the Aorere, Anatoki, Waingaro and Tākaka - were expected to have peaked late on Thursday evening.
"Most of the people in the Aorere Valley and in coastal Golden Bay are aware of the implications of this kind of rainfall, so they'll know there'll be water on the roads, the paddocks will be wet and farmers will have been moving their stock."
He said slips were possible on the Tākaka Hill and particularly on land with Separation Point granite soils - a 10km wide strip that runs for more than 100km between Separation Point in Abel Tasman National Park to Mt Murchison.
Civil defence and emergency management staff would be monitoring the situation overnight.
'A great day for Netflix and staying indoors'
Near Farewell Spit, Golden Bay Holiday Park manager Peter Hartley said the rain began on Wednesday night, and had intensified throughout the day.
"We had 40 millimetres overnight up until 6am this morning, and between 6am and 12pm we had another 30 millimetres and nothing seems to be settling, it is heavy rainfall and it's draining away and not causing surface flooding or any other problems."
He said it was calm and warm despite the rain, rather mild compared to other storms he'd experienced, and it hadn't affected bookings.
"If anything it's had a positive effect because people just don't want to move, they want to just hunker down and wait until the rain stops before moving on.
"Definitely not a great day for golf, it's a great day for Netflix and staying indoors."
Heavy rain continues across Nelson, Marlborough and the West Coast
In Nelson, sports fields have been closed to protect the greens, while Tasman Pine Forests have closed their bike tracks to public recreation access.
Nelson City Council said it would continue to monitor weather across the district as periods of heavy rain were anticipated over the next 24 hours, and surface flooding across the region was likely.
Over in Marlborough, the council's rivers and drainage engineering manager Andy White said the region was also set to get a reasonable amount of rain, but it was well prepared and wasn't expecting any major issues.
"This event is reasonably confined to the northern side of the Wairau River, the Awatere River will also see some higher flows... but it should be a short sharp peak and dropping off after that."
MetService said heavier rain is forecast to occur from 6pm for the Bryant Ranges, including higher hill country behind foothills of Richmond and Nelson, with the possibility of heavy falls through the night.
"This northerly weather event is bringing warm moist air from the tropics. As always, forecasts involving rain and floods require an extra margin for safety and it would be prudent to take a conservative approach and plan for higher floods than suggested, especially if flooding consequences are severe for you," MetService told the Tasman District Council.
Winemakers were halfway through the harvest and Wine Marlborough general manager Marcus Pickens said the forecast deluge was not expected to affect this year's harvest, which is about half-way through.
"If it was prolonged rain for days on end we would be quite concerned but the best news is this one will pass quite quickly, it will be followed by cool weather, we don't want rain then warm, humid conditions, that causes disease pressure, but I think by and large we are hopeful it will skirt us as much as possible."
On the West Coast, Buller Mayor Jamie Cleine said an emergency operations centre had been set up in Westport and sandbags had been made available to residents, as a precaution.
"It is quite short and sharp this weather, so we are not expecting it to cause any major issues on our main rivers, but a lot of the smaller rivers that are fed from the front country are likely to rise really quite rapidly with that level of intensity which could cause a bit of surprise given how dry everything has been."
By the end of Friday, the heaviest rain was expected to have largely moved off the country, though it may linger in eastern Bay of Plenty.
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