New Zealandās climate is about to take a ārapid turnā, a meteorologist says, giving Kiwis a taste of the hotter, drier summer much of the country will experience under El NiƱo.
Thereās now also a good chanceĀ the long-anticipated climate systemĀ - which could be formally declared within weeks - will sit among the strongest El NiƱos seen in the past 80 years, with officials already warning of fire danger and a heightened risk of drought.
For those regions hit hardest by the relentless rain and humidity of three years of La NiƱa, its counterpart climate driver is expected to bring the reverse set-up, with long periods of summer heat and dryness fanned by persistent westerly flows.
āUsing the data from August, this El NiƱo is in with the five strongest that have occurred in the last eight decades,ā Niwa meteorologist Ben Noll said.
Several of those events came with major dry spells: notably the El NiƱo summers of 1972/73, 1982/83 and 1997-98, when a horror event cost the country hundreds of millions of dollars.
āWith its potential intensity being up there with those historically-significant events, thereās definitely a few flags starting to be thrown.ā
This El NiƱo - our first since 2016 - would also come against a background of climate change, and in tandem with another natural driver that had a hand in Australiaās catastrophic bushfires of 2019-20: a positive phase of whatās called the Indian Ocean Dipole.
āThis could dramatically reduce the chance of seeing those tropical moisture plumes as we look ahead - so itās kind of a double-whammy of climate drivers that are going to be coming on quite strongly,ā Noll said.
Before that, however, Noll said things would take a turn within a few weeks, when the atmosphere ācoupledā with oceans already in an El NiƱo-like state.
āIn a New Zealand context, this is going to mean that our own weather patterns are likely to take a rapid turn toward an El NiƱo-like pattern - and thatās expected to start in the second half of September.ā
- El Nino conditions create devastating effects for Pacific nations
- El NiƱo is here and the world must prepare for more extreme heat, UN weather agency warns
- The oceans just reached their hottest temperature on record as El NiƱo looms. Here are 6 things to watch for
- Strong La NiƱas and El NiƱos becoming more frequent as climate changes
As Niwa picked in itsĀ recently-issued spring outlook, Noll expected to see a significant shift in the frequency and intensity of westerly winds, spelling below-normal rainfall and frequently-warm temperatures for the east of both islands.
āWe could be seeing days exceeding 25C during the second half of September,ā he said.
āBy the end of this month, or by mid-October, I think weāll really have had our first real taste of this El NiƱo event, and whatās to come for the rest of 2023.
An incoming El Nino system is raising the risk of drought and wildfire in eastern regions this summer. Photo / Alan Gibson
āFor the likes of Canterbury, eastern Marlborough, northern Otago, Wairarapa and Hawkeās Bay, but also the Bay of Plenty, Coromandel, Auckland and Northland, the weather is going to be quite a contrast to what weāve dealt with the last couple of springs and summers.
āSo, itās about being prepared for the kind of extremes that are going to be possible for the next six months.ā
In Hawkeās Bay, rainfall had already been running at half the normal average, with indications of even drier trends for late September and early October - although a high amount of moisture left in the ground meant there was no imminent threat of local drought.
Hawkeās Bay Regional Council acting science manager Dr Kathleen Kozyniak said it was too early to say if thatād happen this summer - but the developing pattern did point to a heightened risk.
āAs usual, weāll be closely monitoring weather patterns and the status of the regionās rainfall and soil moisture and sharing information through our website and monthly state-of-the-environment reporting,ā Kozyniak told NZME.
Fire and Emergency New Zealandās (Fenz) service delivery wildfire manager Tim Mitchell said conditions forecast for summer were likely to come with higher levels of fire danger on the east coasts of both islands.
Image / Fire and Emergency New Zealand
āGiven this yearās flood events and wet conditions, people will likely find it difficult to understand the wildfire risk New Zealand could be facing soon,ā Mitchell said.
āBut a spell of hot dry windy weather will quickly dry out the grass and vegetation that has grown and will likely grow over the coming months, due to the moist soils and return to warmer weather.
Image / Fire and Emergency NZ
āThis will become a fire risk if not managed.ā
Fenz was urging people in rural and semi-rural areas to prepare now by keeping grass short, moving flammable materials well away from their homes, clearing gutters and accessways to ensure rapid address numbers were visible, and having a plan of action ready.
āNinety-eight per cent of New Zealand wildfires are caused by people and people can do a great deal to prevent wildfires occurring and to help protect themselves and their property.ā
Jamie Morton is a specialist in science and environmental reporting. He joined theĀ HeraldĀ in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
Take your Radio, Podcasts and Music with you