ClimateWatch: How JUNE & WINTER are shaping up as El Niño slowly builds (+13 Maps & Video update)

El Niño continues to slowly form but the weather pattern in NZ still looks to be wetter and warmer for the month of June as a chaotic, neutral, weather pattern continues on this month. Despite June kicking off with colder airflows from the south, the long term trend is for milder than average airflows to return. At least two large low pressure zones look to cross New Zealand in the first half of June bringing variety in wind directions, temperatures and rainfall – but most places receiving rain and leaning wetter than average.

It looks as though, generally speaking, NZ has about 60 to 200mm coming over the first half of June – this is still leaning wetter than average for many regions. In fact, most of the North Island and half of the South Island may be wetter than normal – and all of NZ looks to be half a degree to over 1 degree above normal temperature-wise this coming month.

WeatherWatch.co.nz says the chaotic pattern in NZ means we have distinct lack of frosts so far this year, across both islands and including the Deep South which has had very few below zero nights. In fact some places didn’t have a frost in Autumn 2023, which is remarkable.

Australia’s weather pattern, however, is increasingly looking more El Niño-like, with high pressure being fairly stubborn over the northern half of the country, and rainfall in the southern half of Australia being normal to even below normal. This drier weather pattern to our west is expected to drift more eastwards over NZ later this year. Aussie’s big highs have brought a number of frosty nights to VIC, NSW and even inland QLD. In fact, on the last day of Autumn (May 31) Brisbane was colder than Dunedin at dawn.

Over the coming months WeatherWatch.co.nz expects El Niño to develop, which should encourage more high pressure in the Tasman Sea and north of NZ, and more westerlies over NZ itself. This set up tends to make the West Coast wetter, the North Island’s west coast showery and cloudier (but sometimes drier than average) and eastern and inland parts of New Zealand much drier and warmer than usual.

That’s the text book set-up for El Niño anyway, but of course we’re basically two large mountainous islands partially in the Roaring Forties – so we’ve still got a fair amount of chaos to contend with too. All NZ weather forecasters should factor in the chaos in our part of the world – a good example of our weather chaos is that we just had three consecutive La Niña events, but only the third one altered NZ’s weather pattern – the other two brought drought, which isn’t normally what you’d expect at the top of country in La Niña. It’s too simplistic to simply connect a line from the equator and say this will impact NZ – so we always have to factor in the Roaring Forties/Southern Ocean weather patterns too.

You can read more from Australia’s Bureau of Meteorology (BoM) about the current El Nino set-up here.

WeatherWatch.co.nz says that the general trend for June indicates a big variety of highs and lows in the NZ area and shows we’re not yet in an El Niño weather pattern… its still very much chaotic and neutral for New Zealand.

The Bureau of Meteorology (BoM) says we’re still in an El Niño Watch – meaning El Niño is likely to develop later in 2023.

BoM’s model of all models shows a clear trend towards a moderate to strong El Niño later this year.

A break down of international models with every one of them saying El Niño is very much expected later this year.

El Niño is measured at the equator when sea surface temperatures near South America go up above normal and the western Pacific cools. However western areas are still quite warm and an unrelated marine heatwave continues on around New Zealand. We discuss what this means for NZ in our special video below. Graphic: BoM

This map shows any Meteorological Drought in NZ. It’s good to see the eastern North Island back to normal – but areas that are Moderately to Extremely wet may see another 60 to 150mm in the next few weeks. This map is owned by the NZ Government and produced by the National Institute of Water and Atmospheric Research (NIWA) – a Crown/tax funded public Agency.

THE BIG PICTURE – HOW THE HIGHS & LOWS ARE SHAPING UP IN JUNE…

**WEEK 1** – High pressure to the north of NZ, low pressure to the south – and windy westerlies dominate, turning colder southerly on the first Sunday, then a low pressure zone forms across the entire country for King’s Birthday Monday (visible in the second map below).

**WEEK 2** – Thursday June 8 will see low pressure start to finally move away eastwards from the North Island after dominating most of NZ since King’s Birthday Monday. High pressure to the south and west will give western and southern regions a break for a time – and in fact may bring the first frosty period to Southland and Otago (although it’s borderline still).

**WEEK 3** – Another big low looks to cover all of NZ, this time exiting the Tasman Sea. Australia’s dominant high pressure continues on, especially in Queensland. Meanwhile the Southern Ocean looks stormy south of Australia as we head into mid-June, but high pressure may take a little longer to clear south of NZ around then. Long range maps like this one can change and move around a bit, especially at this more changeable time of year, but the general trend very much shows a big variety of highs and lows in the NZ area and shows we’re not yet in an El Niño weather pattern – its still very much chaotic and neutral for New Zealand.

UPCOMING RAINFALL…

Two lows bring a fair amount of rain to NZ, but dominant high pressure means very little for the top half of Australia and limited rain in the southern half.

A closer up view of NZ’s expected rain. When looking at 15 days of upcoming rain it’s good to “blur your eyes” a little – by that we mean, the heaviest falls and driest areas could still move around a bit, but you can generally see the picture – which shows plenty of rain moving in around the country, and our mountains and ranges will break this up/enhance it further as rain bands move in.

IBM / WeatherWatch long range data shows the North Island, upper South Island and Canterbury all leaning wetter. Coastal Otago may be normal but other regions further south do look to lean drier than usual.

Our IBM / WeatherWatch long term outlook for the season of Winter 2023 looks to be closer to average, if not leaning drier than average. This may be due to the developing El Niño which should encourage more westerlies and high pressure over the Tasman Sea and limit the number of lows tracking over New Zealand.

Farmers in Southland are commenting on the lack of frosts so far this year and June is looking to carry on leaning warmer than average. In saying that, after King’s Birthday weekend the air in Southland, Otago and Canterbury is expected to be normal to below normal temperature-wise. So a cool start to June in the lower part of NZ, but it’s likely to still lean a degree above average as we continue on through the month(as we saw in April and May with some places more than 2 degrees above normal and distinct lack of frosts nationwide).

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Before you add a new comment, take note this story was published on 1 Jun 2023.

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