The closing week of New Zealand's strange summer is forecast to bring more hot and dry conditions to many spots in the north. Photo / Jason Oxenham
The closing week of New Zealand's strange summer is forecast to bring more hot and dry conditions to many spots in the north. Photo / Jason Oxenham
The closing week of New Zealand's strange summer is set to bring more hot and dry conditions to those parched places that need it least.
But more "variable" weather could be just around the corner, a forecaster says.
Amid a lingering ridge of high pressure, a week of mainly fine weather is forecast for Auckland, with daily highs of 25C.
MetService is predicting generally the same picture for Northland, Hamilton, New Plymouth, Wellington, and the North Island's East Coast, although Tauranga may see some showers as the week progresses.
In the South Island, a low pressure system with an accompanying front was forecast to sweep in from Tuesday, bringing strong winds and heavy rain - especially to the West Coast - and hanging about for the rest of the week.
It follows a fine weekend that brought scorching temperatures to many centres, with Hanmer Springs (34C), Blenheim (31.4C), Gisborne (31C) and Alexandra (30C) among the hottest.
Kia ora NZ, here are your maximum temperatures today. Warmest for inland parts of the South Island with Hanmer Springs reaching a top of 34. Meanwhile, more modest temperatures felt along the southeast of the South Island, affected by coastal cloud and onshore breezes. ^PN pic.twitter.com/6iDSrCbSN6
All the while, much of the North Island remained in a dry state - even after heavy rainfall brought more than 100m to rain-starved spots like the Far North and Gisborne.
Officially-designated "hot spots" - or those places with severely to extremely drier than normal soil conditions - could still be found in areas like southern Auckland, northern and eastern Waikato and inland and eastern Bay of Plenty.
Some pockets around the East Cape and southern Hawke's Bay were also still in meteorological drought.
Niwa forecaster Ben Noll said many northern locations could be in for another 10 days of drier than normal conditions before more relief arrived.
"Although places in the northern and eastern North Island would have had a month's worth of rain, give or take, over February, they are still dealing with this long-term dryness - so that wouldn't have alleviated their water woes," he said.
"So we're going to need more, and, looking ahead, there's not really a lot on the horizon for those dry areas."
Noll pointed to Watercare's current dam levels, which were at just under 60 per cent of capacity, compared with a normal average of 82 per cent for this time.
It was notable that Auckland and Northland had seen widespread dryness for the second summer in a row - especially with the presence of a La Nina climate system this season.
Most La Nina-flavoured summers typically came with widespread warmth, but also north-easterly storms, rain about the north and east, dryness about the south and southwest - which was much different to what New Zealand had seen this summer.
Source / Niwa
One contributing factor was the fact the coolest ocean temperatures in the Pacific under this La Nina were found much further west than usual, meaning much of its traditional tropical activity had been centred elsewhere.
The other was warmer-than-average temperatures in the Indian Ocean, which, when combined with the unusual La Nina, delivered a different climate set-up for New Zealand.
Noll said the system, which had peaked and was expected to fade away over coming months, would go down as an outlier in the climate record.
"If you go back through the last 17 or 18 La Ninas, going back to about 1970, just three have brought below-average rainfall to Auckland - so you're basically talking about a 20 per cent chance."
It wasn't yet clear, he said, whether climate change was influencing the occurrence of non-traditional - or so-called "modoki" - La Nina events.
Meanwhile, Noll said there was a chance of more variable weather for the country in early March, with the exiting La Nina opening the door to activity-driving "convective pulses" in the tropics above New Zealand.
"There could be a more favourable up-tick in activity off to the north and west," he said.
"How that manifests itself through the first half of March is far from crystallised but it does look to be going in a more variable direction, after we have these warm ridges of high pressure to round out the summer season."
While New Zealand hadn't yet received an ex-tropical cyclone so far this season - one, on average, was recorded each year - Noll said the risk couldn't be ruled out.
"We've seen a number of cyclones form off to our north this season, but they've generally weakened and passed off to the east," he said.
"There's nothing on the immediate horizon, but let's see what happens during the first in March. There may be nothing, there may be something - but, again, the pattern overall looks to be a bit more variable."
