New Zealand weather: Heavy downpours, strong gusts, thunder as storm topples trees, causes slips in North Island

Powerful winds and heavy downpours have blitzed the North Island overnight, bringing much-needed rain to drought-stricken regions but causing some damage.

A toppled tree has closed a section of State Highway 25 in Waikato, blocking traffic in both directions. Manaia Rd will remain closed until it has been cleared, and motorists have been advised to avoid the area.

A tree covers SH25 in Manaia.
A tree covers SH25 in Manaia. Photo credit: Newshub.

Meanwhile motorists travelling on State Highway 1 between Warkworth and Wellsford in north Auckland are urged to take additional precautions, as the road surface has suffered some damage due to the stormy conditions.

Police are urging drivers to slow down and drive to the conditions on the stretch of road.

Slips and debris were also reported on the roads between Kopu and Hikuai and Tairua and Whitianga in the Coromandel, where strong gusts appear to have overturned a boat moored in Whangamata Harbour and an incredible 204mm of rain fell on Kopu.

A boat overturned in Whangamata Harbour.
A boat overturned in Whangamata Harbour. Photo credit: Newshub.

Metservice meteorologist Tom Adams told Newshub the North Island can expect "more heavy rain and some strong winds" over what's left of Queen's Birthday weekend.

Many areas have already had a good soaking - particularly Northland, where Whangarei had 87mm of rain and Kerikeri 84mm in just 24 hours.

It's some respite for Northland farmers, who have suffered huge losses thanks to the drought conditions that followed an extremely dry New Zealand summer.

"That's some good numbers for people in Northland," Adams said, "and crucially, it's come not in one huge downpour but in a steady few millimetres every hour, which is exactly what people want up there."

Massive gusts have been felt across the upper half of the country too, with Whakaari/White Island getting vigorous winds of 137km/h while the lighthouse at Tiritiri Matangi recorded gusts of 109km/h.

Strong winds are expected on Monday for large swathes of the North Island, while "full-blown thunderstorms" are possible in some regions, Weather Watch says.

Auckland and Waikato are anticipated to receive an additional 20-30mm of rain by Tuesday morning, Weather Watch says, while parts of the Bay of Plenty and the hills between East Cape and Ruatoria could get as much as 60mm.

"Lighter falls, with totals of about 5mm to 10mm, are likely down the western side of the North Island, including Wellington and in the Far North."

Rain is also expected to get more intense through Gisborne and Hawke's Bay, Adams told Newshub.

Even parts of the South Island - which has been largely unscathed until this point - will suffer some of the poor weather on Monday, Weather Watch warns.

"Between Kaikoura and Cape Campbell, there could be as much as 20mm by Tuesday morning... Fiordland will pick up a few drizzly showers later in the day or tonight in a northwesterly flow there.

"However, totals drop the further west and south you go from there, with Christchurch only looking at 1-2mm tonight."

While it hasn't been wet down south, it has been cold. Dunedin Airport recorded a temperature of just -7degC at 7am on Monday.