Latest weather forecast: Saturday soggiest in rain-spoiled Labour weekend

• Labour weekend is forecast to be wet around New Zealand, with the heaviest rain likely on Saturday.
• It comes after a moisture-packed weather system brings more intense deluges to the South Island’s West Coast.
• Forecasters are also picking toasty temperatures for parts of the country late this week, with Napier and Hastings set to hit 28C tomorrow.

Saturday looks to be the wettest of a rain-spoiled long weekend for many parts of New Zealand – but not before a blob of warm air from Australia makes its influence felt.

Three days out from Labour weekend, the forecast holds little for Kiwis who’d hoped for some mid-spring sunshine.

MetService is forecasting rain and potentially strong northerlies for Auckland on Saturday, followed by a shift to showers and cooler westerly winds on Sunday and Monday.

It’s a similar picture in centres including Whangārei, Hamilton, Tauranga, Napier, New Plymouth, Palmerston North and Wellington, with the heaviest falls likely on Saturday.

“The Bay of Plenty may be drier on Sunday and Monday, as winds shift from northerly to more westerly, but we are expecting showers over most of the country on Sunday and Monday,” MetService meteorologist Claire O’Connor said.

Long weekend rain and showers are also on the cards for southern centres including Blenheim, Nelson, Westport, Christchurch and Dunedin.

Ahead of that rain, meteorologists are focused on a moisture-packed flow again bringing heavy downpours to the South Island’s West Coast over the next two days.

MetService has issued several orange heavy rain warnings for these regions, with as much as 300mm possible in Westland’s ranges over a 28-hour period beginning late tonight.

With that heavy rain comes wind: northwest winds could reach gale-strength in exposed areas of the Canterbury High Country throughout tomorrow – as well as in Wairarapa, Wellington and the Marlborough Sounds overnight Thursday and into Friday morning.

O’Connor said these warm flows also had potential to drive up river levels by melting snow in mountain headwaters of southern river catchments.

“We just want to make sure people are aware of that, because even if you don’t see a lot of rain falling around you, river levels are likely to still rise.”

The New Zealand Mountain Safety Council also urged trampers to be wary of weather conditions ahead of the weekend.

“It’s essential to have a clear plan, tell someone where you’re going and pack for all conditions, for both day walks and overnight tramps,” the council’s chief executive Mike Daisley said.

For northern eastern regions, the warm flow, travelling across the Tasman Sea from Australia, was already helping drive up temperatures.

MetService is forecasting highs in the early 20s for centres including Auckland, Tauranga, Hamilton and Christchurch around the end of the week, with Napier and Hastings possibly seeing a summer-like high of 28C on Thursday.

This week’s weather continues a month of extreme contrasts in rainfall for New Zealand.

Niwa reported Dunedin and other parts of Otago have received more than triple their October normal rainfall – while Napier’s totals were sitting at just 12% of normal at the start of the week.

That pattern was a result of repeated westerly flows – a typical hallmark of spring weather – bringing moisture-packed fronts to places like the southwest and drier conditions to the northeast.

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.

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