The country is in the middle of a 'winter-like surge' as polar air plunges temperatures. Video / NZ Herald / MetService
The storm in space has been upgraded from severe to extreme, the highest category scientists use to measure these types of galactic weather events.
Transpower has issued a “grid emergency” notice in New Zealand and is removing some transmission lines from operation due to the onset of the geomagnetic storm as a precaution.
A spokesperson for the agency, which operates the New Zealand power grid, said the storm was likely to affect Earth over the weekend because of significant solar activity.
The space weather event was upgraded from a G4 geomagnetic storm to a G5.
“As part of our contingency plan, we are removing some transmission lines from service across the South Island as a precaution. In order to do this, we have to issue a grid emergency notice, however, this initial action should not impact supply of electricity to consumers.”
Transpower Grid Development executive general manager John Clarke said he’s been told the amount of disturbance around the earth in this weather event is similar to the last G5 storm over 20 years ago.
Clarke told NZME at the level of severity they’re seeing at the moment the storm should not impact the ability for Kiwis to use electricity.
“This is sort of a rare event, it’s worldwide, it’s not unique to New Zealand. All grid operaters will be thinking about out how they’re configuring their power systems right now with the level of solar activity. I think consumers can be confident that we’ve done enough research to know what we need to do at the moment.”
While electricity does “wonderful things”, he said people should always be prepared for the unexpected and have a plan to cope if the power goes off for a day or two.
AP reported the storm could produce northern lights in the US and potentially disrupt communications over the weekend. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa, the agency said.
A US National Oceanic and Atmospheric Administration forecaster said these storms, ranked on a scale of 1 to 5, posed a risk for high-voltage transmission lines for power grids, not the electrical lines ordinarily found in people’s homes.
The last extreme geomagnetic storm hit Earth in 2003, taking out power in Sweden and damaging power transformers in South Africa.
The National Institute of Water and Atmospheric Research (Niwa) said the coldest temperature was recorded at Cass, Canterbury, where it fell to -9.7C. MetService said Christchurch hit -6.3C, Masterton fell to -3.5C and Palmerston North dropped to -3.1C.
Transpower issued a warning notice a day earlier and people were asked to conserve electricity by turning down their heaters, not charging their electronic devices or vehicles, and delaying any washing or drying.
An extra layer of clothing was required this morning 🧊
A few of our stations even broke their record low May temperatures.
Christchurch Airport was just 0.1°C from their May record with data back to 1954! pic.twitter.com/pLDbl01OOe
The efforts people made to limit their power usage, along with reductions from industrial users and extra electricity generation, meant the country avoided a major grid emergency and power cuts never eventuated, Transpower said.
Even though the cold temperatures will remain, Transpower chief executive Alison Andrew said there was no reason to expect any further need to conserve electricity over the weekend.
“Thank you to all New Zealanders who acted to reduce their electricity demand this morning. It made a difference, and we appreciate it,” Andrew said.
Auckland in for sunny Saturday, 15C: Forecasts around NZ
MetService has forecast a fine Saturday and Sunday for Auckland. Today, the temperature was tipped to reach 15C and 16C tomorrow.
Cloudy mornings were expected for next week, with rain setting in from Wednesday.
In Wellington, MetService forecasts a mostly cloudy Saturday with occasional showers. It should clear to fine in the afternoon and the temperature should reach 12C. Sunday should reach 12C and the day should remain partly cloudy.
Christchurch had a mostly cloudy forecast for Saturday. Some showers were possible, mostly confined to the Banks Peninsula and clearing by midday, MetService said. It should reach 12C and on Sunday, with fine conditions, temperatures should rise to 14C.
A run of chilly days brought snow to Porters Pass, Canterbury, this week. Photo / George Heard
Saturday would see cloudy periods in Dunedin and a high of 11C, while Sunday would turn cloudy in the afternoon and temperatures should reach 14C.
MetService meteorologist Mmathapelo Makgabutlane said this May provided a stark contrast to last year, being a lot colder.
“Many may recall the tropical-feeling temperatures of May 2023, where places like Auckland and Hamilton experienced record-breaking warm nights. However, this year, expect an overnight drop to mid-single digits in Auckland City and early morning temperatures hovering near freezing in Hamilton,” she said.
Raphael Franks is an Auckland-based reporter who covers breaking news. He joined the Herald as a Te Rito cadet in 2022.
