MetService issued the warning at 8.44am with a line of electrical storms lying from Rūātoki North to Waimana to Kutarere.

“This line of severe thunderstorms is moving towards the south-southeast, and is expected to lie from Matahi to Waimana to the Waioeka Gorge at 9.07am, and near the Waioeka Gorge at 9.37am.”

The forecaster warned the thunderstorms would be accompanied by torrential rain and came with a threat of flash flooding.

At the same time the electrical storm was due to hit Waioeka Gorge was closed by flooding and slips.

NZ Transport Authority Waka Kotahi and police said the highway was now closed between Matawai and Waioeka due to an earlier slip and warned motorists to avoid the area or delay their journey if possible.

MetService has lifted an earlier severe thunderstorm warning for the Bay of Plenty that came into force earlier this morning, but a heavy rain warning remains in place.

The forecaster has been issuing fresh thunderstorm warnings for parts of the North Island throughout this morning as individual storm cells develop.

An earlier warning, issued just after 6am, affected Ōpōtiki, Western Bay of Plenty, Whakatāne, Kawerau and Rotorua and was lifted at 6.50am.

“These thunderstorms are expected to be accompanied by very heavy rain,” the forecaster said.

“Very heavy rain can cause surface and/or flash flooding about streams, gullies and urban areas, and make driving conditions extremely hazardous.”

A heavy rain warning from last night is still in place until 11am for Bay of Plenty and Rotorua.

A severe thunderstorm watch is also in force until 11am for Gisborne, Hawke’s Bay and Waikato. MetService said there was a “moderate risk” of severe thunderstorms bringing downpours with rainfall of 25-40mm/h.

“Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.”

It follows Thursday’s severe weather which saw several reported tornadoes sweeping across the North Island, with reports of damage to buildings and downed trees and fences.

Mixed bag for today’s weather

Variable weather is forecast across New Zealand today, with warmer temperatures in the North Island and colder conditions in the South.

MetService meteorologist Michael Pauley told the Herald the low-pressure system, which brought heavy rain and thunderstorms yesterday, would move off New Zealand.

“This pushes east where, around about midday, we’re seeing that main rain band lying just over East Cape, so that pushes off over the afternoon,” he said.

“Things will be getting a bit finer for the upper part of the North Island. We do see a few showers but they’re going to be relatively isolated.”

However, a southerly is forecast to push up the eastern side of the North Island.

“[This] could bring a chance of thunderstorms and hail in the afternoon and evening,” Pauley said.

“In the South Island, those periods of rain will gradually ease.

“But there is quite a bit of moisture trapped down there so that will take quite a while to get rid of all that moisture in the eastern regions, around Christchurch and Canterbury.”

Pauley said northern parts of the North Island could still see some heavy showers this morning.

“They have a fair few showers to cross them during the course of the day.

“The easing trend across the country is the general gist of it.”

Temperatures across the South Island are forecast to be cooler than normal for January.

“Wānaka has a max of 15C so does Queenstown. For Wānaka, it’s more than 8C below average for this time of year,” Pauley said.

“Christchurch is looking at a high of 16C and Blenheim 19C.”

In the North Island, Auckland and Hamilton are forecast to reach a high of 25C today, while Tauranga could reach a high of 27C.

Warm temperatures in the bottom half of the North Island are set to hold out for one more day before tumbling on Saturday.

“Hastings is forecast to get a high of 30C, whereas Saturday is looking at a high of 19C,” Pauley said.

The forecaster pointed to a southerly moving across the North Island as the cause of the cold temperatures.

“The low pushes off east and drags the southerlies in behind it.”

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