Unprecedented El Niño 'just getting started', Kiwis warned to prepare
People in water-reliant sectors, including farmers and those living on tank water, are being warned to prepare for particularly dry months ahead.
El Niño, which was officially declared in New Zealand at the beginning of July, is still strengthening and won’t peak for a few months.
Earth Sciences New Zealand (ESNZ) principal scientist Chris Brandolino told the Herald that the weather phenomenon would probably peak around November or December. Even after its peak, the comedown would be gradual.
“El Niño is just getting started.”
He explained that El Niño was only “one quarter of the ‘blame pie’” in terms of the overall weather outlook, but that was in average terms.
“Because this is a historically strong El Niño, the slice of the pie is going to be larger.”
The outlook included a “mid-August rainy period”, with “unusual wetness” for about a week, before a drier spell began.
“From late August and into September, we will see more persistent dryness, particularly for the North Island,” he said.
“Western and the lower South Island are the areas that will probably buck that trend.”
Brandolino said dryness “will be a theme through to the end of October and beyond”, particularly for the upper North Island, from Waikato north. While that did not mean no rainfall at all, we should expect below-normal falls at least until the end of October.
“Conversely, for the western and lower South Island, those areas should expect a wetter-than-usual three-month period.
“It’s fair to say that the risk for dryness in the eastern and upper part of both islands will continue as we move beyond October and for the rest of the calendar year.”
Dry windy periods mean increased wildfire risk
Brandolino warned of potentially windy periods, mainly, but not exclusively, for the South Island, particularly the western and lower areas. That wind could also mean warmer temperatures.
In September, there would be periods of airflow from Australia, bringing “spiky temperatures” and unusually warm air for the South Island, accentuated as it moved across the Southern Alps. This would create a foehn effect, making the downwind side of a mountain (in this case, the eastern South Island) much warmer and drier than the upwind side.
Warmer temperatures combined with the strong winds increase the risk of wildfires.
Kiwis warned to prepare for dry months ahead
With rainfall below normal for much of the country, particularly the northern and eastern part of both islands, people needed to start preparing, Brandolino said.
“People in water-reliant sectors, like farmers or people on tank water, are going to have to start thinking about what dryness means for them.
“Dryness is a longer-term threat. People in water-reliant sectors – farms, people on tank water – think about a plan. Think about, in years past, what has happened in your local area when there’s been dryness. Trim back vegetation to reduce fire risk. It’s best to have a plan and not need it [rather] than need a plan and not have it.”
Forecasters agree that this year’s climate pattern could rival the intensity of the six strongest El Nino events on the modern record, with some dubbing it a “Super El Niño”.
The current heatwaves in parts of Europe and across the Northern Hemisphere were also linked in part to El Niño and the warmer Pacific Ocean.
Brandolino told RNZ last month that heat from the ocean and the atmosphere was “getting redistributed across the globe” and the heatwaves were not isolated phenomena.
They were happening against a background of temperature increases, meaning the hottest days were getting hotter. The same could be expected in New Zealand.
“We’re going to be seeing our own version of that – perhaps not 40C or 44C like we’ve seen in Europe – but certainly that spikiness is something we’re expecting,” he said last month.
Take your Radio, Podcasts and Music with you
Get the iHeart App
Get more of the radio, music and podcasts you love with the FREE iHeart app. Scan the QR code to download now.
Download from the app stores
Stream unlimited music, thousands of radio stations and podcasts all in one app. iHeart is easy to use and all FREE
